diff --git a/.travis.yml b/.travis.yml
index c7170f74..1a031804 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,7 +10,6 @@ matrix:
 install:
   - pip install codecov
 script:
-  - if [[ $TRAVIS_PYTHON_VERSION != '2.7' ]]; then python -m lib2to3 -w -n tests; fi
   - coverage run --source github/tests setup.py test
 after_success:
   - codecov
diff --git a/github/AuthenticatedUser.py b/github/AuthenticatedUser.py
index 80400a27..37a9785c 100644
--- a/github/AuthenticatedUser.py
+++ b/github/AuthenticatedUser.py
@@ -40,6 +40,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
 import github.GithubObject
@@ -57,7 +58,8 @@ import github.Authorization
 import github.Notification
 import github.Migration
 
-import Consts
+from . import Consts
+import six
 
 
 class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
@@ -372,7 +374,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param email: string
         :rtype: None
         """
-        assert all(isinstance(element, (str, unicode)) for element in emails), emails
+        assert all(isinstance(element, (str, six.text_type)) for element in emails), emails
         post_parameters = emails
         headers, data = self._requester.requestJsonAndCheck(
             "POST",
@@ -440,12 +442,12 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param onetime_password: string
         :rtype: :class:`github.Authorization.Authorization`
         """
-        assert scopes is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in scopes), scopes
-        assert note is github.GithubObject.NotSet or isinstance(note, (str, unicode)), note
-        assert note_url is github.GithubObject.NotSet or isinstance(note_url, (str, unicode)), note_url
-        assert client_id is github.GithubObject.NotSet or isinstance(client_id, (str, unicode)), client_id
-        assert client_secret is github.GithubObject.NotSet or isinstance(client_secret, (str, unicode)), client_secret
-        assert onetime_password is None or isinstance(onetime_password, (str, unicode)), onetime_password
+        assert scopes is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in scopes), scopes
+        assert note is github.GithubObject.NotSet or isinstance(note, (str, six.text_type)), note
+        assert note_url is github.GithubObject.NotSet or isinstance(note_url, (str, six.text_type)), note_url
+        assert client_id is github.GithubObject.NotSet or isinstance(client_id, (str, six.text_type)), client_id
+        assert client_secret is github.GithubObject.NotSet or isinstance(client_secret, (str, six.text_type)), client_secret
+        assert onetime_password is None or isinstance(onetime_password, (str, six.text_type)), onetime_password
         post_parameters = dict()
         if scopes is not github.GithubObject.NotSet:
             post_parameters["scopes"] = scopes
@@ -491,11 +493,11 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.Gist.Gist`
         """
         assert isinstance(public, bool), public
-        assert all(isinstance(element, github.InputFileContent) for element in files.itervalues()), files
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
+        assert all(isinstance(element, github.InputFileContent) for element in six.itervalues(files)), files
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
         post_parameters = {
             "public": public,
-            "files": {key: value._identity for key, value in files.iteritems()},
+            "files": {key: value._identity for key, value in six.iteritems(files)},
         }
         if description is not github.GithubObject.NotSet:
             post_parameters["description"] = description
@@ -513,8 +515,8 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param key: string
         :rtype: :class:`github.UserKey.UserKey`
         """
-        assert isinstance(title, (str, unicode)), title
-        assert isinstance(key, (str, unicode)), key
+        assert isinstance(title, (str, six.text_type)), title
+        assert isinstance(key, (str, six.text_type)), key
         post_parameters = {
             "title": title,
             "key": key,
@@ -550,17 +552,17 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param allow_rebase_merge: bool
         :rtype: :class:`github.Repository.Repository`
         """
-        assert isinstance(name, (str, unicode)), name
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
-        assert homepage is github.GithubObject.NotSet or isinstance(homepage, (str, unicode)), homepage
+        assert isinstance(name, (str, six.text_type)), name
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
+        assert homepage is github.GithubObject.NotSet or isinstance(homepage, (str, six.text_type)), homepage
         assert private is github.GithubObject.NotSet or isinstance(private, bool), private
         assert has_issues is github.GithubObject.NotSet or isinstance(has_issues, bool), has_issues
         assert has_wiki is github.GithubObject.NotSet or isinstance(has_wiki, bool), has_wiki
         assert has_downloads is github.GithubObject.NotSet or isinstance(has_downloads, bool), has_downloads
         assert has_projects is github.GithubObject.NotSet or isinstance(has_projects, bool), has_projects
         assert auto_init is github.GithubObject.NotSet or isinstance(auto_init, bool), auto_init
-        assert license_template is github.GithubObject.NotSet or isinstance(license_template, (str, unicode)), license_template
-        assert gitignore_template is github.GithubObject.NotSet or isinstance(gitignore_template, (str, unicode)), gitignore_template
+        assert license_template is github.GithubObject.NotSet or isinstance(license_template, (str, six.text_type)), license_template
+        assert gitignore_template is github.GithubObject.NotSet or isinstance(gitignore_template, (str, six.text_type)), gitignore_template
         assert allow_squash_merge is github.GithubObject.NotSet or isinstance(allow_squash_merge, bool), allow_squash_merge
         assert allow_merge_commit is github.GithubObject.NotSet or isinstance(allow_merge_commit, bool), allow_merge_commit
         assert allow_rebase_merge is github.GithubObject.NotSet or isinstance(allow_rebase_merge, bool), allow_rebase_merge
@@ -612,13 +614,13 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param bio: string
         :rtype: None
         """
-        assert name is github.GithubObject.NotSet or isinstance(name, (str, unicode)), name
-        assert email is github.GithubObject.NotSet or isinstance(email, (str, unicode)), email
-        assert blog is github.GithubObject.NotSet or isinstance(blog, (str, unicode)), blog
-        assert company is github.GithubObject.NotSet or isinstance(company, (str, unicode)), company
-        assert location is github.GithubObject.NotSet or isinstance(location, (str, unicode)), location
+        assert name is github.GithubObject.NotSet or isinstance(name, (str, six.text_type)), name
+        assert email is github.GithubObject.NotSet or isinstance(email, (str, six.text_type)), email
+        assert blog is github.GithubObject.NotSet or isinstance(blog, (str, six.text_type)), blog
+        assert company is github.GithubObject.NotSet or isinstance(company, (str, six.text_type)), company
+        assert location is github.GithubObject.NotSet or isinstance(location, (str, six.text_type)), location
         assert hireable is github.GithubObject.NotSet or isinstance(hireable, bool), hireable
-        assert bio is github.GithubObject.NotSet or isinstance(bio, (str, unicode)), bio
+        assert bio is github.GithubObject.NotSet or isinstance(bio, (str, six.text_type)), bio
         post_parameters = dict()
         if name is not github.GithubObject.NotSet:
             post_parameters["name"] = name
@@ -647,7 +649,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.Authorization.Authorization`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             "/authorizations/" + str(id)
@@ -742,11 +744,11 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param since: datetime.datetime
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Issue.Issue`
         """
-        assert filter is github.GithubObject.NotSet or isinstance(filter, (str, unicode)), filter
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
+        assert filter is github.GithubObject.NotSet or isinstance(filter, (str, six.text_type)), filter
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
         assert labels is github.GithubObject.NotSet or all(isinstance(element, github.Label.Label) for element in labels), labels
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
         url_parameters = dict()
         if filter is not github.GithubObject.NotSet:
@@ -780,11 +782,11 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param since: datetime.datetime
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Issue.Issue`
         """
-        assert filter is github.GithubObject.NotSet or isinstance(filter, (str, unicode)), filter
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
+        assert filter is github.GithubObject.NotSet or isinstance(filter, (str, six.text_type)), filter
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
         assert labels is github.GithubObject.NotSet or all(isinstance(element, github.Label.Label) for element in labels), labels
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
         url_parameters = dict()
         if filter is not github.GithubObject.NotSet:
@@ -812,7 +814,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.UserKey.UserKey`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             "/user/keys/" + str(id)
@@ -837,7 +839,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.Notification.Notification`
         """
 
-        assert isinstance(id, (str, unicode)), id
+        assert isinstance(id, (str, six.text_type)), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             "/notifications/threads/" + id
@@ -908,7 +910,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param name: string
         :rtype: :class:`github.Repository.Repository`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             "/repos/" + self.login + "/" + name
@@ -925,11 +927,11 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param direction: string
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
         """
-        assert visibility is github.GithubObject.NotSet or isinstance(visibility, (str, unicode)), visibility
-        assert affiliation is github.GithubObject.NotSet or isinstance(affiliation, (str, unicode)), affiliation
-        assert type is github.GithubObject.NotSet or isinstance(type, (str, unicode)), type
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert visibility is github.GithubObject.NotSet or isinstance(visibility, (str, six.text_type)), visibility
+        assert affiliation is github.GithubObject.NotSet or isinstance(affiliation, (str, six.text_type)), affiliation
+        assert type is github.GithubObject.NotSet or isinstance(type, (str, six.text_type)), type
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         url_parameters = dict()
         if visibility is not github.GithubObject.NotSet:
             url_parameters["visibility"] = visibility
@@ -1082,7 +1084,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :param email: string
         :rtype: None
         """
-        assert all(isinstance(element, (str, unicode)) for element in emails), emails
+        assert all(isinstance(element, (str, six.text_type)) for element in emails), emails
         post_parameters = emails
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
@@ -1176,7 +1178,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.Migration.Migration`
         """
         assert isinstance(repos, (list, tuple)), repos
-        assert all(isinstance(repo, (str, unicode)) for repo in repos), repos
+        assert all(isinstance(repo, (str, six.text_type)) for repo in repos), repos
         assert lock_repositories is github.GithubObject.NotSet or isinstance(lock_repositories, bool), lock_repositories
         assert exclude_attachments is github.GithubObject.NotSet or isinstance(exclude_attachments, bool), exclude_attachments
         post_parameters = {
diff --git a/github/Authorization.py b/github/Authorization.py
index 22c7ad3b..faea16ca 100644
--- a/github/Authorization.py
+++ b/github/Authorization.py
@@ -30,9 +30,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.AuthorizationApplication
+import six
 
 
 class Authorization(github.GithubObject.CompletableGithubObject):
@@ -135,11 +137,11 @@ class Authorization(github.GithubObject.CompletableGithubObject):
         :param note_url: string
         :rtype: None
         """
-        assert scopes is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in scopes), scopes
-        assert add_scopes is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in add_scopes), add_scopes
-        assert remove_scopes is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in remove_scopes), remove_scopes
-        assert note is github.GithubObject.NotSet or isinstance(note, (str, unicode)), note
-        assert note_url is github.GithubObject.NotSet or isinstance(note_url, (str, unicode)), note_url
+        assert scopes is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in scopes), scopes
+        assert add_scopes is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in add_scopes), add_scopes
+        assert remove_scopes is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in remove_scopes), remove_scopes
+        assert note is github.GithubObject.NotSet or isinstance(note, (str, six.text_type)), note
+        assert note_url is github.GithubObject.NotSet or isinstance(note_url, (str, six.text_type)), note_url
         post_parameters = dict()
         if scopes is not github.GithubObject.NotSet:
             post_parameters["scopes"] = scopes
diff --git a/github/AuthorizationApplication.py b/github/AuthorizationApplication.py
index c6b9bc50..ab3e93e5 100644
--- a/github/AuthorizationApplication.py
+++ b/github/AuthorizationApplication.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Branch.py b/github/Branch.py
index 07f615fd..7f5e4773 100644
--- a/github/Branch.py
+++ b/github/Branch.py
@@ -33,6 +33,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.BranchProtection
@@ -40,7 +41,8 @@ import github.Commit
 import github.RequiredPullRequestReviews
 import github.RequiredStatusChecks
 
-import Consts
+from . import Consts
+import six
 
 
 class Branch(github.GithubObject.NonCompletableGithubObject):
@@ -125,10 +127,10 @@ class Branch(github.GithubObject.NonCompletableGithubObject):
         changing. Use edit_required_status_checks() to avoid this.
         """
         assert strict is github.GithubObject.NotSet or isinstance(strict, bool), strict
-        assert contexts is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in contexts), contexts
+        assert contexts is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in contexts), contexts
         assert enforce_admins is github.GithubObject.NotSet or isinstance(enforce_admins, bool), enforce_admins
-        assert dismissal_users is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in dismissal_users), dismissal_users
-        assert dismissal_teams is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in dismissal_teams), dismissal_teams
+        assert dismissal_users is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in dismissal_users), dismissal_users
+        assert dismissal_teams is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in dismissal_teams), dismissal_teams
         assert dismiss_stale_reviews is github.GithubObject.NotSet or isinstance(dismiss_stale_reviews, bool), dismiss_stale_reviews
         assert require_code_owner_reviews is github.GithubObject.NotSet or isinstance(require_code_owner_reviews, bool), require_code_owner_reviews
         assert required_approving_review_count is github.GithubObject.NotSet or isinstance(required_approving_review_count, int), required_approving_review_count
@@ -207,7 +209,7 @@ class Branch(github.GithubObject.NonCompletableGithubObject):
         :contexts: list of strings
         """
         assert strict is github.GithubObject.NotSet or isinstance(strict, bool), strict
-        assert contexts is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in contexts), contexts
+        assert contexts is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in contexts), contexts
 
         post_parameters = {}
         if strict is not github.GithubObject.NotSet:
@@ -250,8 +252,8 @@ class Branch(github.GithubObject.NonCompletableGithubObject):
         :require_code_owner_reviews: bool
         :required_approving_review_count: int
         """
-        assert dismissal_users is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in dismissal_users), dismissal_users
-        assert dismissal_teams is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in dismissal_teams), dismissal_teams
+        assert dismissal_users is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in dismissal_users), dismissal_users
+        assert dismissal_teams is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in dismissal_teams), dismissal_teams
         assert dismiss_stale_reviews is github.GithubObject.NotSet or isinstance(dismiss_stale_reviews, bool), dismiss_stale_reviews
         assert require_code_owner_reviews is github.GithubObject.NotSet or isinstance(require_code_owner_reviews, bool), require_code_owner_reviews
         assert required_approving_review_count is github.GithubObject.NotSet or isinstance(required_approving_review_count, int), required_approving_review_count
@@ -343,7 +345,7 @@ class Branch(github.GithubObject.NonCompletableGithubObject):
         :calls: `POST /repos/:owner/:repo/branches/:branch/protection/restrictions <https://developer.github.com/v3/repos/branches>`_
         :users: list of strings
         """
-        assert all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in users), users
+        assert all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in users), users
 
         headers, data = self._requester.requestJsonAndCheck(
             "POST",
@@ -356,7 +358,7 @@ class Branch(github.GithubObject.NonCompletableGithubObject):
         :calls: `POST /repos/:owner/:repo/branches/:branch/protection/restrictions <https://developer.github.com/v3/repos/branches>`_
         :teams: list of strings
         """
-        assert all(isinstance(element, (str, unicode)) or isinstance(element, (str, unicode)) for element in teams), teams
+        assert all(isinstance(element, (str, six.text_type)) or isinstance(element, (str, six.text_type)) for element in teams), teams
 
         headers, data = self._requester.requestJsonAndCheck(
             "POST",
diff --git a/github/BranchProtection.py b/github/BranchProtection.py
index cf48147a..caf1bfd9 100644
--- a/github/BranchProtection.py
+++ b/github/BranchProtection.py
@@ -22,6 +22,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
diff --git a/github/Clones.py b/github/Clones.py
index b8c1adc7..1f3faac6 100644
--- a/github/Clones.py
+++ b/github/Clones.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Commit.py b/github/Commit.py
index fb6afa21..a15fdc6e 100644
--- a/github/Commit.py
+++ b/github/Commit.py
@@ -32,6 +32,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.PaginatedList
 
@@ -42,6 +43,7 @@ import github.CommitCombinedStatus
 import github.File
 import github.CommitStats
 import github.CommitComment
+import six
 
 
 class Commit(github.GithubObject.CompletableGithubObject):
@@ -141,10 +143,10 @@ class Commit(github.GithubObject.CompletableGithubObject):
         :param position: integer
         :rtype: :class:`github.CommitComment.CommitComment`
         """
-        assert isinstance(body, (str, unicode)), body
-        assert line is github.GithubObject.NotSet or isinstance(line, (int, long)), line
-        assert path is github.GithubObject.NotSet or isinstance(path, (str, unicode)), path
-        assert position is github.GithubObject.NotSet or isinstance(position, (int, long)), position
+        assert isinstance(body, (str, six.text_type)), body
+        assert line is github.GithubObject.NotSet or isinstance(line, six.integer_types), line
+        assert path is github.GithubObject.NotSet or isinstance(path, (str, six.text_type)), path
+        assert position is github.GithubObject.NotSet or isinstance(position, six.integer_types), position
         post_parameters = {
             "body": body,
         }
@@ -170,10 +172,10 @@ class Commit(github.GithubObject.CompletableGithubObject):
         :param context: string
         :rtype: :class:`github.CommitStatus.CommitStatus`
         """
-        assert isinstance(state, (str, unicode)), state
-        assert target_url is github.GithubObject.NotSet or isinstance(target_url, (str, unicode)), target_url
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
-        assert context is github.GithubObject.NotSet or isinstance(context, (str, unicode)), context
+        assert isinstance(state, (str, six.text_type)), state
+        assert target_url is github.GithubObject.NotSet or isinstance(target_url, (str, six.text_type)), target_url
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
+        assert context is github.GithubObject.NotSet or isinstance(context, (str, six.text_type)), context
         post_parameters = {
             "state": state,
         }
diff --git a/github/CommitCombinedStatus.py b/github/CommitCombinedStatus.py
index 9cf21dcf..3516ea39 100644
--- a/github/CommitCombinedStatus.py
+++ b/github/CommitCombinedStatus.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.CommitStatus
diff --git a/github/CommitComment.py b/github/CommitComment.py
index d5224a11..6a085168 100644
--- a/github/CommitComment.py
+++ b/github/CommitComment.py
@@ -32,10 +32,12 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.NamedUser
 
-import Consts
+from . import Consts
+import six
 
 
 class CommitComment(github.GithubObject.CompletableGithubObject):
@@ -150,7 +152,7 @@ class CommitComment(github.GithubObject.CompletableGithubObject):
         :param body: string
         :rtype: None
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "body": body,
         }
@@ -182,7 +184,7 @@ class CommitComment(github.GithubObject.CompletableGithubObject):
         :param reaction_type: string
         :rtype: :class:`github.Reaction.Reaction`
         """
-        assert isinstance(reaction_type, (str, unicode)), "reaction type should be a string"
+        assert isinstance(reaction_type, (str, six.text_type)), "reaction type should be a string"
         assert reaction_type in ["+1", "-1", "laugh", "confused", "heart", "hooray"], \
             "Invalid reaction type (https://developer.github.com/v3/reactions/#reaction-types)"
 
diff --git a/github/CommitStats.py b/github/CommitStats.py
index e98fb210..e1b78b76 100644
--- a/github/CommitStats.py
+++ b/github/CommitStats.py
@@ -29,6 +29,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/CommitStatus.py b/github/CommitStatus.py
index 2fa5d58c..91b05d70 100644
--- a/github/CommitStatus.py
+++ b/github/CommitStatus.py
@@ -32,6 +32,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
diff --git a/github/Comparison.py b/github/Comparison.py
index 22d01beb..cfcbc9a0 100644
--- a/github/Comparison.py
+++ b/github/Comparison.py
@@ -29,6 +29,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.Commit
diff --git a/github/ContentFile.py b/github/ContentFile.py
index e597a099..10b30ff0 100644
--- a/github/ContentFile.py
+++ b/github/ContentFile.py
@@ -31,6 +31,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import base64
 import sys
 
diff --git a/github/Download.py b/github/Download.py
index 7e31593c..2b7fb92e 100644
--- a/github/Download.py
+++ b/github/Download.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Event.py b/github/Event.py
index 5b9fb9af..6a92a010 100644
--- a/github/Event.py
+++ b/github/Event.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.Organization
diff --git a/github/File.py b/github/File.py
index a07baaf0..7fc09776 100644
--- a/github/File.py
+++ b/github/File.py
@@ -32,6 +32,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Gist.py b/github/Gist.py
index 0164ded6..6115f852 100644
--- a/github/Gist.py
+++ b/github/Gist.py
@@ -33,6 +33,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.PaginatedList
 
@@ -40,6 +41,7 @@ import github.GistComment
 import github.NamedUser
 import github.GistFile
 import github.GistHistoryState
+import six
 
 
 class Gist(github.GithubObject.CompletableGithubObject):
@@ -208,7 +210,7 @@ class Gist(github.GithubObject.CompletableGithubObject):
         :param body: string
         :rtype: :class:`github.GistComment.GistComment`
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "body": body,
         }
@@ -247,13 +249,13 @@ class Gist(github.GithubObject.CompletableGithubObject):
         :param files: dict of string to :class:`github.InputFileContent.InputFileContent`
         :rtype: None
         """
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
-        assert files is github.GithubObject.NotSet or all(element is None or isinstance(element, github.InputFileContent) for element in files.itervalues()), files
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
+        assert files is github.GithubObject.NotSet or all(element is None or isinstance(element, github.InputFileContent) for element in six.itervalues(files)), files
         post_parameters = dict()
         if description is not github.GithubObject.NotSet:
             post_parameters["description"] = description
         if files is not github.GithubObject.NotSet:
-            post_parameters["files"] = {key: None if value is None else value._identity for key, value in files.iteritems()}
+            post_parameters["files"] = {key: None if value is None else value._identity for key, value in six.iteritems(files)}
         headers, data = self._requester.requestJsonAndCheck(
             "PATCH",
             self.url,
@@ -267,7 +269,7 @@ class Gist(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.GistComment.GistComment`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/comments/" + str(id)
diff --git a/github/GistComment.py b/github/GistComment.py
index c62c0e6c..2de766f7 100644
--- a/github/GistComment.py
+++ b/github/GistComment.py
@@ -30,9 +30,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
+import six
 
 
 class GistComment(github.GithubObject.CompletableGithubObject):
@@ -107,7 +109,7 @@ class GistComment(github.GithubObject.CompletableGithubObject):
         :param body: string
         :rtype: None
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "body": body,
         }
diff --git a/github/GistFile.py b/github/GistFile.py
index c9245116..a16829a1 100644
--- a/github/GistFile.py
+++ b/github/GistFile.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/GistHistoryState.py b/github/GistHistoryState.py
index 01fc3add..bd01a79b 100644
--- a/github/GistHistoryState.py
+++ b/github/GistHistoryState.py
@@ -29,6 +29,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
diff --git a/github/GitAuthor.py b/github/GitAuthor.py
index d7f5dc8a..6532f96e 100644
--- a/github/GitAuthor.py
+++ b/github/GitAuthor.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/GitBlob.py b/github/GitBlob.py
index 2db328d9..367db983 100644
--- a/github/GitBlob.py
+++ b/github/GitBlob.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/GitCommit.py b/github/GitCommit.py
index 92e903a6..9198240e 100644
--- a/github/GitCommit.py
+++ b/github/GitCommit.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.GitAuthor
diff --git a/github/GitObject.py b/github/GitObject.py
index ce2fd71f..b03c7fdb 100644
--- a/github/GitObject.py
+++ b/github/GitObject.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/GitRef.py b/github/GitRef.py
index b35e3ab7..9c929d60 100644
--- a/github/GitRef.py
+++ b/github/GitRef.py
@@ -30,9 +30,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.GitObject
+import six
 
 
 class GitRef(github.GithubObject.CompletableGithubObject):
@@ -84,7 +86,7 @@ class GitRef(github.GithubObject.CompletableGithubObject):
         :param force: bool
         :rtype: None
         """
-        assert isinstance(sha, (str, unicode)), sha
+        assert isinstance(sha, (str, six.text_type)), sha
         assert force is github.GithubObject.NotSet or isinstance(force, bool), force
         post_parameters = {
             "sha": sha,
diff --git a/github/GitRelease.py b/github/GitRelease.py
index 2b050749..8ab79fdb 100644
--- a/github/GitRelease.py
+++ b/github/GitRelease.py
@@ -35,10 +35,12 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 from os.path import basename
 import github.GithubObject
 import github.NamedUser
 import github.GitReleaseAsset
+import six
 
 
 class GitRelease(github.GithubObject.CompletableGithubObject):
@@ -187,13 +189,13 @@ class GitRelease(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.GitRelease.GitRelease`
         """
         assert tag_name is github.GithubObject.NotSet              \
-            or isinstance(tag_name, (str, unicode)),               \
+            or isinstance(tag_name, (str, six.text_type)),               \
             'tag_name must be a str/unicode object'
         assert target_commitish is github.GithubObject.NotSet      \
-            or isinstance(target_commitish, (str, unicode)),       \
+            or isinstance(target_commitish, (str, six.text_type)),       \
             'target_commitish must be a str/unicode object'
-        assert isinstance(name, (str, unicode)), name
-        assert isinstance(message, (str, unicode)), message
+        assert isinstance(name, (str, six.text_type)), name
+        assert isinstance(message, (str, six.text_type)), message
         assert isinstance(draft, bool), draft
         assert isinstance(prerelease, bool), prerelease
         if tag_name is github.GithubObject.NotSet:
@@ -221,9 +223,9 @@ class GitRelease(github.GithubObject.CompletableGithubObject):
         :calls: `POST https://<upload_url>/repos/:owner/:repo/releases/:release_id/assets <https://developer.github.com/v3/repos/releases/#upload-a-release-asset>`_
         :rtype: :class:`github.GitReleaseAsset.GitReleaseAsset`
         """
-        assert isinstance(path, (str, unicode)), path
-        assert isinstance(label, (str, unicode)), label
-        assert name is github.GithubObject.NotSet or isinstance(name, (str, unicode)), name
+        assert isinstance(path, (str, six.text_type)), path
+        assert isinstance(label, (str, six.text_type)), label
+        assert name is github.GithubObject.NotSet or isinstance(name, (str, six.text_type)), name
 
         post_parameters = {
             "label": label
diff --git a/github/GitReleaseAsset.py b/github/GitReleaseAsset.py
index 1f899e7e..a92848a4 100644
--- a/github/GitReleaseAsset.py
+++ b/github/GitReleaseAsset.py
@@ -25,7 +25,9 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
+import six
 
 
 class GitReleaseAsset(github.GithubObject.CompletableGithubObject):
@@ -164,8 +166,8 @@ class GitReleaseAsset(github.GithubObject.CompletableGithubObject):
         Update asset metadata.
         :rtype: github.GitReleaseAsset.GitReleaseAsset
         """
-        assert isinstance(name, (str, unicode)), name
-        assert isinstance(label, (str, unicode)), label
+        assert isinstance(name, (str, six.text_type)), name
+        assert isinstance(label, (str, six.text_type)), label
         post_parameters = {
             "name": name,
             "label": label
diff --git a/github/GitTag.py b/github/GitTag.py
index 059fc9f1..5b9a41dd 100644
--- a/github/GitTag.py
+++ b/github/GitTag.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.GitAuthor
diff --git a/github/GitTree.py b/github/GitTree.py
index c9aca0d1..a5c0fd79 100644
--- a/github/GitTree.py
+++ b/github/GitTree.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.GitTreeElement
diff --git a/github/GitTreeElement.py b/github/GitTreeElement.py
index cf7d21e8..eadf7d1e 100644
--- a/github/GitTreeElement.py
+++ b/github/GitTreeElement.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/GithubObject.py b/github/GithubObject.py
index af8587e2..b5462cf0 100644
--- a/github/GithubObject.py
+++ b/github/GithubObject.py
@@ -32,12 +32,14 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import sys
 import datetime
 from operator import itemgetter
 
-import GithubException
-import Consts
+from . import GithubException
+from . import Consts
+import six
 
 atLeastPython3 = sys.hexversion >= 0x03000000
 
@@ -140,18 +142,18 @@ class GithubObject(object):
         elif isinstance(value, type):
             try:
                 return _ValuedAttribute(transform(value))
-            except Exception, e:
+            except Exception as e:
                 return _BadAttribute(value, type, e)
         else:
             return _BadAttribute(value, type)
 
     @staticmethod
     def _makeStringAttribute(value):
-        return GithubObject.__makeSimpleAttribute(value, (str, unicode))
+        return GithubObject.__makeSimpleAttribute(value, (str, six.text_type))
 
     @staticmethod
     def _makeIntAttribute(value):
-        return GithubObject.__makeSimpleAttribute(value, (int, long))
+        return GithubObject.__makeSimpleAttribute(value, six.integer_types)
 
     @staticmethod
     def _makeBoolAttribute(value):
@@ -163,7 +165,7 @@ class GithubObject(object):
 
     @staticmethod
     def _makeTimestampAttribute(value):
-        return GithubObject.__makeTransformedAttribute(value, (int, long), datetime.datetime.utcfromtimestamp)
+        return GithubObject.__makeTransformedAttribute(value, six.integer_types, datetime.datetime.utcfromtimestamp)
 
     @staticmethod
     def _makeDatetimeAttribute(value):
@@ -177,14 +179,14 @@ class GithubObject(object):
             else:
                 return datetime.datetime.strptime(s, "%Y-%m-%dT%H:%M:%SZ")
 
-        return GithubObject.__makeTransformedAttribute(value, (str, unicode), parseDatetime)
+        return GithubObject.__makeTransformedAttribute(value, (str, six.text_type), parseDatetime)
 
     def _makeClassAttribute(self, klass, value):
         return GithubObject.__makeTransformedAttribute(value, dict, lambda value: klass(self._requester, self._headers, value, completed=False))
 
     @staticmethod
     def _makeListOfStringsAttribute(value):
-        return GithubObject.__makeSimpleListAttribute(value, (str, unicode))
+        return GithubObject.__makeSimpleListAttribute(value, (str, six.text_type))
 
     @staticmethod
     def _makeListOfIntsAttribute(value):
@@ -205,10 +207,10 @@ class GithubObject(object):
             return _BadAttribute(value, [dict])
 
     def _makeDictOfStringsToClassesAttribute(self, klass, value):
-        if isinstance(value, dict) and all(isinstance(key, (str, unicode)) and isinstance(element, dict) for key, element in value.iteritems()):
-            return _ValuedAttribute(dict((key, klass(self._requester, self._headers, element, completed=False)) for key, element in value.iteritems()))
+        if isinstance(value, dict) and all(isinstance(key, (str, six.text_type)) and isinstance(element, dict) for key, element in six.iteritems(value)):
+            return _ValuedAttribute(dict((key, klass(self._requester, self._headers, element, completed=False)) for key, element in six.iteritems(value)))
         else:
-            return _BadAttribute(value, {(str, unicode): dict})
+            return _BadAttribute(value, {(str, six.text_type): dict})
 
     @property
     def etag(self):
@@ -230,11 +232,11 @@ class GithubObject(object):
         """
         def format_params(params):
             if atLeastPython3:
-                items = params.items()
+                items = list(params.items())
             else:
                 items = list(params.items())
             for k, v in sorted(items, key=itemgetter(0), reverse=True):
-                isText = isinstance(v, (str, unicode))
+                isText = isinstance(v, (str, six.text_type))
                 if isText and not atLeastPython3:
                     v = v.encode('utf-8')
                 yield '{k}="{v}"'.format(k=k, v=v) if isText else '{k}={v}'.format(k=k, v=v)
diff --git a/github/GitignoreTemplate.py b/github/GitignoreTemplate.py
index 79c708be..650885dd 100644
--- a/github/GitignoreTemplate.py
+++ b/github/GitignoreTemplate.py
@@ -29,6 +29,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Hook.py b/github/Hook.py
index 3866368f..30b2ab9f 100644
--- a/github/Hook.py
+++ b/github/Hook.py
@@ -31,9 +31,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.HookResponse
+import six
 
 
 class Hook(github.GithubObject.CompletableGithubObject):
@@ -153,11 +155,11 @@ class Hook(github.GithubObject.CompletableGithubObject):
         :param active: bool
         :rtype: None
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         assert isinstance(config, dict), config
-        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in events), events
-        assert add_events is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in add_events), add_events
-        assert remove_events is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in remove_events), remove_events
+        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in events), events
+        assert add_events is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in add_events), add_events
+        assert remove_events is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in remove_events), remove_events
         assert active is github.GithubObject.NotSet or isinstance(active, bool), active
         post_parameters = {
             "name": name,
diff --git a/github/HookDescription.py b/github/HookDescription.py
index d2f43063..0a971dc7 100644
--- a/github/HookDescription.py
+++ b/github/HookDescription.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/HookResponse.py b/github/HookResponse.py
index 72b02375..1a8172ba 100644
--- a/github/HookResponse.py
+++ b/github/HookResponse.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/InputFileContent.py b/github/InputFileContent.py
index b9e26e7e..33b6481e 100644
--- a/github/InputFileContent.py
+++ b/github/InputFileContent.py
@@ -28,7 +28,9 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
+import six
 
 
 class InputFileContent(object):
@@ -42,8 +44,8 @@ class InputFileContent(object):
         :param new_name: string
         """
 
-        assert isinstance(content, (str, unicode)), content
-        assert new_name is github.GithubObject.NotSet or isinstance(new_name, (str, unicode)), new_name
+        assert isinstance(content, (str, six.text_type)), content
+        assert new_name is github.GithubObject.NotSet or isinstance(new_name, (str, six.text_type)), new_name
         self.__newName = new_name
         self.__content = content
 
diff --git a/github/InputGitAuthor.py b/github/InputGitAuthor.py
index a5cd596b..667fd54c 100644
--- a/github/InputGitAuthor.py
+++ b/github/InputGitAuthor.py
@@ -30,7 +30,9 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
+import six
 
 
 class InputGitAuthor(object):
@@ -45,9 +47,9 @@ class InputGitAuthor(object):
         :param date: string
         """
 
-        assert isinstance(name, (str, unicode)), name
-        assert isinstance(email, (str, unicode)), email
-        assert date is github.GithubObject.NotSet or isinstance(date, (str, unicode)), date  # @todo Datetime?
+        assert isinstance(name, (str, six.text_type)), name
+        assert isinstance(email, (str, six.text_type)), email
+        assert date is github.GithubObject.NotSet or isinstance(date, (str, six.text_type)), date  # @todo Datetime?
 
         self.__name = name
         self.__email = email
diff --git a/github/InputGitTreeElement.py b/github/InputGitTreeElement.py
index 0fec87d7..78c354cc 100644
--- a/github/InputGitTreeElement.py
+++ b/github/InputGitTreeElement.py
@@ -28,7 +28,9 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
+import six
 
 
 class InputGitTreeElement(object):
@@ -45,11 +47,11 @@ class InputGitTreeElement(object):
         :param sha: string
         """
 
-        assert isinstance(path, (str, unicode)), path
-        assert isinstance(mode, (str, unicode)), mode
-        assert isinstance(type, (str, unicode)), type
-        assert content is github.GithubObject.NotSet or isinstance(content, (str, unicode)), content
-        assert sha is github.GithubObject.NotSet or isinstance(sha, (str, unicode)), sha
+        assert isinstance(path, (str, six.text_type)), path
+        assert isinstance(mode, (str, six.text_type)), mode
+        assert isinstance(type, (str, six.text_type)), type
+        assert content is github.GithubObject.NotSet or isinstance(content, (str, six.text_type)), content
+        assert sha is github.GithubObject.NotSet or isinstance(sha, (str, six.text_type)), sha
         self.__path = path
         self.__mode = mode
         self.__type = type
diff --git a/github/Installation.py b/github/Installation.py
index 79690d5f..7f6c36b6 100644
--- a/github/Installation.py
+++ b/github/Installation.py
@@ -25,6 +25,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.PaginatedList
 
@@ -39,7 +40,7 @@ import github.Event
 import github.Authorization
 import github.Notification
 
-import Consts
+from . import Consts
 
 INTEGRATION_PREVIEW_HEADERS = {"Accept": Consts.mediaTypeIntegrationPreview}
 
diff --git a/github/InstallationAuthorization.py b/github/InstallationAuthorization.py
index d0a47313..d95fe0db 100644
--- a/github/InstallationAuthorization.py
+++ b/github/InstallationAuthorization.py
@@ -25,6 +25,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.PaginatedList
 import github.NamedUser
diff --git a/github/Invitation.py b/github/Invitation.py
index 6b66f388..cee0b5a4 100644
--- a/github/Invitation.py
+++ b/github/Invitation.py
@@ -24,6 +24,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Issue.py b/github/Issue.py
index b1a40be4..cc8a482a 100644
--- a/github/Issue.py
+++ b/github/Issue.py
@@ -42,7 +42,8 @@
 #                                                                              #
 ################################################################################
 
-import urllib
+from __future__ import absolute_import
+import six.moves.urllib.request, six.moves.urllib.parse, six.moves.urllib.error
 import datetime
 import github.GithubObject
 import github.PaginatedList
@@ -56,7 +57,8 @@ import github.IssueComment
 import github.IssuePullRequest
 import github.Reaction
 
-import Consts
+from . import Consts
+import six
 
 
 class Issue(github.GithubObject.CompletableGithubObject):
@@ -280,7 +282,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param assignee: :class:`github.NamedUser.NamedUser` or string
         :rtype: None
         """
-        assert all(isinstance(element, (github.NamedUser.NamedUser, str, unicode)) for element in assignees), assignees
+        assert all(isinstance(element, (github.NamedUser.NamedUser, str, six.text_type)) for element in assignees), assignees
         post_parameters = {"assignees": [assignee.login if isinstance(assignee, github.NamedUser.NamedUser) else assignee for assignee in assignees]}
         headers, data = self._requester.requestJsonAndCheck(
             "POST",
@@ -295,7 +297,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param label: :class:`github.Label.Label` or string
         :rtype: None
         """
-        assert all(isinstance(element, (github.Label.Label, str, unicode)) for element in labels), labels
+        assert all(isinstance(element, (github.Label.Label, str, six.text_type)) for element in labels), labels
         post_parameters = [label.name if isinstance(label, github.Label.Label) else label for label in labels]
         headers, data = self._requester.requestJsonAndCheck(
             "POST",
@@ -309,7 +311,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param body: string
         :rtype: :class:`github.IssueComment.IssueComment`
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "body": body,
         }
@@ -342,20 +344,20 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param labels: list of string
         :rtype: None
         """
-        assert title is github.GithubObject.NotSet or isinstance(title, (str, unicode)), title
-        assert body is github.GithubObject.NotSet or isinstance(body, (str, unicode)), body
-        assert assignee is github.GithubObject.NotSet or assignee is None or isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, unicode)), assignee
-        assert assignees is github.GithubObject.NotSet or all(isinstance(element, github.NamedUser.NamedUser) or isinstance(element, (str, unicode)) for element in assignees), assignees
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
+        assert title is github.GithubObject.NotSet or isinstance(title, (str, six.text_type)), title
+        assert body is github.GithubObject.NotSet or isinstance(body, (str, six.text_type)), body
+        assert assignee is github.GithubObject.NotSet or assignee is None or isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, six.text_type)), assignee
+        assert assignees is github.GithubObject.NotSet or all(isinstance(element, github.NamedUser.NamedUser) or isinstance(element, (str, six.text_type)) for element in assignees), assignees
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
         assert milestone is github.GithubObject.NotSet or milestone is None or isinstance(milestone, github.Milestone.Milestone), milestone
-        assert labels is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in labels), labels
+        assert labels is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in labels), labels
         post_parameters = dict()
         if title is not github.GithubObject.NotSet:
             post_parameters["title"] = title
         if body is not github.GithubObject.NotSet:
             post_parameters["body"] = body
         if assignee is not github.GithubObject.NotSet:
-            if isinstance(assignee, (str, unicode)):
+            if isinstance(assignee, (str, six.text_type)):
                 post_parameters["assignee"] = assignee
             else:
                 post_parameters["assignee"] = assignee._identity if assignee else ''
@@ -380,7 +382,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param lock_reason: string
         :rtype: None
         """
-        assert isinstance(lock_reason, (str, unicode)), lock_reason
+        assert isinstance(lock_reason, (str, six.text_type)), lock_reason
         put_parameters = dict()
         put_parameters["lock_reason"] = lock_reason
         headers, data = self._requester.requestJsonAndCheck(
@@ -406,7 +408,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.IssueComment.IssueComment`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self._parentUrl(self.url) + "/comments/" + str(id)
@@ -461,7 +463,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param assignee: :class:`github.NamedUser.NamedUser` or string
         :rtype: None
         """
-        assert all(isinstance(element, (github.NamedUser.NamedUser, str, unicode)) for element in assignees), assignees
+        assert all(isinstance(element, (github.NamedUser.NamedUser, str, six.text_type)) for element in assignees), assignees
         post_parameters = {"assignees": [assignee.login if isinstance(assignee, github.NamedUser.NamedUser) else assignee for assignee in assignees]}
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
@@ -476,11 +478,11 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param label: :class:`github.Label.Label` or string
         :rtype: None
         """
-        assert isinstance(label, (github.Label.Label, str, unicode)), label
+        assert isinstance(label, (github.Label.Label, str, six.text_type)), label
         if isinstance(label, github.Label.Label):
             label = label._identity
         else:
-            label = urllib.quote(label)
+            label = six.moves.urllib.parse.quote(label)
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
             self.url + "/labels/" + label
@@ -492,7 +494,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param labels: list of :class:`github.Label.Label` or strings
         :rtype: None
         """
-        assert all(isinstance(element, (github.Label.Label, str, unicode)) for element in labels), labels
+        assert all(isinstance(element, (github.Label.Label, str, six.text_type)) for element in labels), labels
         post_parameters = [label.name if isinstance(label, github.Label.Label) else label for label in labels]
         headers, data = self._requester.requestJsonAndCheck(
             "PUT",
@@ -519,7 +521,7 @@ class Issue(github.GithubObject.CompletableGithubObject):
         :param reaction_type: string
         :rtype: :class:`github.Reaction.Reaction`
         """
-        assert isinstance(reaction_type, (str, unicode)), "reaction type should be a string"
+        assert isinstance(reaction_type, (str, six.text_type)), "reaction type should be a string"
         assert reaction_type in ["+1", "-1", "laugh", "confused", "heart", "hooray"], \
             "Invalid reaction type (https://developer.github.com/v3/reactions/#reaction-types)"
 
diff --git a/github/IssueComment.py b/github/IssueComment.py
index dc689c5a..2e2c659f 100644
--- a/github/IssueComment.py
+++ b/github/IssueComment.py
@@ -33,10 +33,12 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.NamedUser
 
-import Consts
+from . import Consts
+import six
 
 
 class IssueComment(github.GithubObject.CompletableGithubObject):
@@ -127,7 +129,7 @@ class IssueComment(github.GithubObject.CompletableGithubObject):
         :param body: string
         :rtype: None
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "body": body,
         }
@@ -159,7 +161,7 @@ class IssueComment(github.GithubObject.CompletableGithubObject):
         :param reaction_type: string
         :rtype: :class:`github.Reaction.Reaction`
         """
-        assert isinstance(reaction_type, (str, unicode)), "reaction type should be a string"
+        assert isinstance(reaction_type, (str, six.text_type)), "reaction type should be a string"
         assert reaction_type in ["+1", "-1", "laugh", "confused", "heart", "hooray"], \
             "Invalid reaction type (https://developer.github.com/v3/reactions/#reaction-types)"
 
diff --git a/github/IssueEvent.py b/github/IssueEvent.py
index e746ae0e..e813d7f6 100644
--- a/github/IssueEvent.py
+++ b/github/IssueEvent.py
@@ -31,6 +31,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.Issue
diff --git a/github/IssuePullRequest.py b/github/IssuePullRequest.py
index f35f4da0..e3f637e0 100644
--- a/github/IssuePullRequest.py
+++ b/github/IssuePullRequest.py
@@ -29,6 +29,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Label.py b/github/Label.py
index e2efac20..edffca7d 100644
--- a/github/Label.py
+++ b/github/Label.py
@@ -31,11 +31,13 @@
 #                                                                              #
 ################################################################################
 
-import urllib
+from __future__ import absolute_import
+import six.moves.urllib.request, six.moves.urllib.parse, six.moves.urllib.error
 
 import github.GithubObject
 
-import Consts
+from . import Consts
+import six
 
 
 class Label(github.GithubObject.CompletableGithubObject):
@@ -96,9 +98,9 @@ class Label(github.GithubObject.CompletableGithubObject):
         :param description: string
         :rtype: None
         """
-        assert isinstance(name, (str, unicode)), name
-        assert isinstance(color, (str, unicode)), color
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
+        assert isinstance(name, (str, six.text_type)), name
+        assert isinstance(color, (str, six.text_type)), color
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
         post_parameters = {
             "name": name,
             "color": color,
@@ -115,7 +117,7 @@ class Label(github.GithubObject.CompletableGithubObject):
 
     @property
     def _identity(self):
-        return urllib.quote(self.name)
+        return six.moves.urllib.parse.quote(self.name)
 
     def _initAttributes(self):
         self._color = github.GithubObject.NotSet
diff --git a/github/Legacy.py b/github/Legacy.py
index 23267d69..22fabc6e 100644
--- a/github/Legacy.py
+++ b/github/Legacy.py
@@ -29,9 +29,11 @@
 #                                                                              #
 ################################################################################
 
-import urlparse
+from __future__ import absolute_import
+import six.moves.urllib.parse
 
 import github.PaginatedList
+import six
 
 
 class PaginatedList(github.PaginatedList.PaginatedListBase):
@@ -55,7 +57,7 @@ class PaginatedList(github.PaginatedList.PaginatedListBase):
         return self.get_page(page)
 
     def get_page(self, page):
-        assert isinstance(page, (int, long)), page
+        assert isinstance(page, six.integer_types), page
         args = dict(self.__args)
         if page != 0:
             args["start_page"] = page + 1
@@ -133,7 +135,7 @@ def convertRepo(attributes):
 def convertIssue(attributes):
     convertedAttributes = {
         "number": attributes["number"],
-        "url": "/repos" + urlparse.urlparse(attributes["html_url"]).path,
+        "url": "/repos" + six.moves.urllib.parse.urlparse(attributes["html_url"]).path,
         "user": {"login": attributes["user"], "url": "/users/" + attributes["user"]},
     }
     if "labels" in attributes:  # pragma no branch
diff --git a/github/License.py b/github/License.py
index 31014942..b6f0b1a2 100644
--- a/github/License.py
+++ b/github/License.py
@@ -22,6 +22,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.PaginatedList
 
diff --git a/github/MainClass.py b/github/MainClass.py
index f41c2015..afdf9d46 100644
--- a/github/MainClass.py
+++ b/github/MainClass.py
@@ -48,6 +48,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
 import pickle
@@ -57,24 +58,25 @@ import requests
 import jwt
 import urllib3
 
-from Requester import Requester
-import AuthenticatedUser
-import NamedUser
-import Gist
+from .Requester import Requester
+from . import AuthenticatedUser
+from . import NamedUser
+from . import Gist
 import github.PaginatedList
-import Repository
-import Installation
-import License
-import Topic
+from . import Repository
+from . import Installation
+from . import License
+from . import Topic
 import github.GithubObject
-import HookDescription
-import GitignoreTemplate
-import RateLimit
-import InstallationAuthorization
-import GithubException
-import Invitation
+from . import HookDescription
+from . import GitignoreTemplate
+from . import RateLimit
+from . import InstallationAuthorization
+from . import GithubException
+from . import Invitation
 
-import Consts
+from . import Consts
+import six
 
 atLeastPython3 = sys.hexversion >= 0x03000000
 
@@ -106,14 +108,14 @@ class Github(object):
         :param retry: int or urllib3.util.retry.Retry object
         """
 
-        assert login_or_token is None or isinstance(login_or_token, (str, unicode)), login_or_token
-        assert password is None or isinstance(password, (str, unicode)), password
-        assert jwt is None or isinstance(jwt, (str, unicode)), jwt
-        assert isinstance(base_url, (str, unicode)), base_url
-        assert isinstance(timeout, (int, long)), timeout
-        assert client_id is None or isinstance(client_id, (str, unicode)), client_id
-        assert client_secret is None or isinstance(client_secret, (str, unicode)), client_secret
-        assert user_agent is None or isinstance(user_agent, (str, unicode)), user_agent
+        assert login_or_token is None or isinstance(login_or_token, (str, six.text_type)), login_or_token
+        assert password is None or isinstance(password, (str, six.text_type)), password
+        assert jwt is None or isinstance(jwt, (str, six.text_type)), jwt
+        assert isinstance(base_url, (str, six.text_type)), base_url
+        assert isinstance(timeout, six.integer_types), timeout
+        assert client_id is None or isinstance(client_id, (str, six.text_type)), client_id
+        assert client_secret is None or isinstance(client_secret, (str, six.text_type)), client_secret
+        assert user_agent is None or isinstance(user_agent, (str, six.text_type)), user_agent
         assert isinstance(api_preview, (bool))
         assert retry is None or isinstance(retry, (int)) or isinstance(retry, (urllib3.util.Retry))
         self.__requester = Requester(login_or_token, password, jwt, base_url, timeout, client_id, client_secret, user_agent, per_page, api_preview, verify, retry)
@@ -194,7 +196,7 @@ class Github(object):
         :rtype: :class:`github.License.License`
         """
 
-        assert isinstance(key, (str, unicode)), key
+        assert isinstance(key, (str, six.text_type)), key
         headers, data = self.__requester.requestJsonAndCheck(
             "GET",
             "/licenses/" + key
@@ -222,7 +224,7 @@ class Github(object):
         :param login: string
         :rtype: :class:`github.NamedUser.NamedUser`
         """
-        assert login is github.GithubObject.NotSet or isinstance(login, (str, unicode)), login
+        assert login is github.GithubObject.NotSet or isinstance(login, (str, six.text_type)), login
         if login is github.GithubObject.NotSet:
             return AuthenticatedUser.AuthenticatedUser(self.__requester, {}, {"url": "/user"}, completed=False)
         else:
@@ -238,7 +240,7 @@ class Github(object):
         :param since: integer
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
         """
-        assert since is github.GithubObject.NotSet or isinstance(since, (int, long)), since
+        assert since is github.GithubObject.NotSet or isinstance(since, six.integer_types), since
         url_parameters = dict()
         if since is not github.GithubObject.NotSet:
             url_parameters["since"] = since
@@ -255,7 +257,7 @@ class Github(object):
         :param login: string
         :rtype: :class:`github.Organization.Organization`
         """
-        assert isinstance(login, (str, unicode)), login
+        assert isinstance(login, (str, six.text_type)), login
         headers, data = self.__requester.requestJsonAndCheck(
             "GET",
             "/orgs/" + login
@@ -268,7 +270,7 @@ class Github(object):
         :param since: integer
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Organization.Organization`
         """
-        assert since is github.GithubObject.NotSet or isinstance(since, (int, long)), since
+        assert since is github.GithubObject.NotSet or isinstance(since, six.integer_types), since
         url_parameters = dict()
         if since is not github.GithubObject.NotSet:
             url_parameters["since"] = since
@@ -284,8 +286,8 @@ class Github(object):
         :calls: `GET /repos/:owner/:repo <http://developer.github.com/v3/repos>`_ or `GET /repositories/:id <http://developer.github.com/v3/repos>`_
         :rtype: :class:`github.Repository.Repository`
         """
-        assert isinstance(full_name_or_id, (str, unicode, int, long)), full_name_or_id
-        url_base = "/repositories/" if isinstance(full_name_or_id, int) or isinstance(full_name_or_id, long) else "/repos/"
+        assert isinstance(full_name_or_id, (str, six.text_type, int, int)), full_name_or_id
+        url_base = "/repositories/" if isinstance(full_name_or_id, int) or isinstance(full_name_or_id, int) else "/repos/"
         url = "%s%s" % (url_base, full_name_or_id)
         if lazy:
             return Repository.Repository(self.__requester, {}, {"url": url}, completed=False)
@@ -302,7 +304,7 @@ class Github(object):
         :param visibility: string ('all','public')
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
         """
-        assert since is github.GithubObject.NotSet or isinstance(since, (int, long)), since
+        assert since is github.GithubObject.NotSet or isinstance(since, six.integer_types), since
         url_parameters = dict()
         if since is not github.GithubObject.NotSet:
             url_parameters["since"] = since
@@ -335,7 +337,7 @@ class Github(object):
         :param id: string
         :rtype: :class:`github.Gist.Gist`
         """
-        assert isinstance(id, (str, unicode)), id
+        assert isinstance(id, (str, six.text_type)), id
         headers, data = self.__requester.requestJsonAndCheck(
             "GET",
             "/gists/" + id
@@ -368,7 +370,7 @@ class Github(object):
         :param qualifiers: keyword dict query qualifiers
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
         """
-        assert isinstance(query, (str, unicode)), query
+        assert isinstance(query, (str, six.text_type)), query
         url_parameters = dict()
         if sort is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
             assert sort in ('stars', 'forks', 'updated'), sort
@@ -403,7 +405,7 @@ class Github(object):
         :param qualifiers: keyword dict query qualifiers
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
         """
-        assert isinstance(query, (str, unicode)), query
+        assert isinstance(query, (str, six.text_type)), query
         url_parameters = dict()
         if sort is not github.GithubObject.NotSet:
             assert sort in ('followers', 'repositories', 'joined'), sort
@@ -438,7 +440,7 @@ class Github(object):
         :param qualifiers: keyword dict query qualifiers
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Issue.Issue`
         """
-        assert isinstance(query, (str, unicode)), query
+        assert isinstance(query, (str, six.text_type)), query
         url_parameters = dict()
         if sort is not github.GithubObject.NotSet:
             assert sort in ('comments', 'created', 'updated'), sort
@@ -474,7 +476,7 @@ class Github(object):
         :param qualifiers: keyword dict query qualifiers
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.ContentFile.ContentFile`
         """
-        assert isinstance(query, (str, unicode)), query
+        assert isinstance(query, (str, six.text_type)), query
         url_parameters = dict()
         if sort is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
             assert sort in ('indexed',), sort
@@ -512,7 +514,7 @@ class Github(object):
         :param qualifiers: keyword dict query qualifiers
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Commit.Commit`
         """
-        assert isinstance(query, (str, unicode)), query
+        assert isinstance(query, (str, six.text_type)), query
         url_parameters = dict()
         if sort is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
             assert sort in ('author-date', 'committer-date'), sort
@@ -548,7 +550,7 @@ class Github(object):
         :param qualifiers: keyword dict query qualifiers
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Topic.Topic`
         """
-        assert isinstance(query, (str, unicode)), query
+        assert isinstance(query, (str, six.text_type)), query
         url_parameters = dict()
 
         query_chunks = []
@@ -578,7 +580,7 @@ class Github(object):
         :param context: :class:`github.Repository.Repository`
         :rtype: string
         """
-        assert isinstance(text, (str, unicode)), text
+        assert isinstance(text, (str, six.text_type)), text
         assert context is github.GithubObject.NotSet or isinstance(context, github.Repository.Repository), context
         post_parameters = {
             "text": text
@@ -599,7 +601,7 @@ class Github(object):
         :param name: string
         :rtype: :class:`github.HookDescription.HookDescription`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         headers, attributes = self.__requester.requestJsonAndCheck(
             "GET",
             "/hooks/" + name
@@ -633,7 +635,7 @@ class Github(object):
         :calls: `GET /gitignore/templates/:name <http://developer.github.com/v3/gitignore>`_
         :rtype: :class:`github.GitignoreTemplate.GitignoreTemplate`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         headers, attributes = self.__requester.requestJsonAndCheck(
             "GET",
             "/gitignore/templates/" + name
@@ -707,7 +709,7 @@ class GithubIntegration(object):
         self.base_url = base_url
         self.integration_id = integration_id
         self.private_key = private_key
-        assert isinstance(base_url, (str, unicode)), base_url
+        assert isinstance(base_url, (str, six.text_type)), base_url
 
     def create_jwt(self, expiration=60):
         """
diff --git a/github/Migration.py b/github/Migration.py
index fc14be6f..38f796c8 100644
--- a/github/Migration.py
+++ b/github/Migration.py
@@ -32,12 +32,14 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.PaginatedList
 
 import github.NamedUser
 
-import Consts
+from . import Consts
+import six
 
 
 class Migration(github.GithubObject.CompletableGithubObject):
@@ -176,7 +178,7 @@ class Migration(github.GithubObject.CompletableGithubObject):
         :param repo_name: str
         :rtype: None
         """
-        assert isinstance(repo_name, (str, unicode)), repo_name
+        assert isinstance(repo_name, (str, six.text_type)), repo_name
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
             self.url + "/repos/" + repo_name + "/lock",
diff --git a/github/Milestone.py b/github/Milestone.py
index 18d0e5ea..bd0343aa 100644
--- a/github/Milestone.py
+++ b/github/Milestone.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
 import github.GithubObject
@@ -37,6 +38,7 @@ import github.PaginatedList
 
 import github.NamedUser
 import github.Label
+import six
 
 
 class Milestone(github.GithubObject.CompletableGithubObject):
@@ -170,9 +172,9 @@ class Milestone(github.GithubObject.CompletableGithubObject):
         :param due_on: date
         :rtype: None
         """
-        assert isinstance(title, (str, unicode)), title
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
+        assert isinstance(title, (str, six.text_type)), title
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
         assert due_on is github.GithubObject.NotSet or isinstance(due_on, datetime.date), due_on
         post_parameters = {
             "title": title,
diff --git a/github/NamedUser.py b/github/NamedUser.py
index 8286859f..0fd2b50c 100644
--- a/github/NamedUser.py
+++ b/github/NamedUser.py
@@ -37,6 +37,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
 import github.GithubObject
@@ -49,6 +50,7 @@ import github.Permissions
 import github.Plan
 import github.Organization
 import github.Event
+import six
 
 
 class NamedUser(github.GithubObject.CompletableGithubObject):
@@ -536,7 +538,7 @@ class NamedUser(github.GithubObject.CompletableGithubObject):
         :param name: string
         :rtype: :class:`github.Repository.Repository`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             "/repos/" + self.login + "/" + name
@@ -552,9 +554,9 @@ class NamedUser(github.GithubObject.CompletableGithubObject):
         :param direction: string
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
         """
-        assert type is github.GithubObject.NotSet or isinstance(type, (str, unicode)), type
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert type is github.GithubObject.NotSet or isinstance(type, (str, six.text_type)), type
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         url_parameters = dict()
         if type is not github.GithubObject.NotSet:
             url_parameters["type"] = type
diff --git a/github/Notification.py b/github/Notification.py
index b62d75f6..72947ac0 100644
--- a/github/Notification.py
+++ b/github/Notification.py
@@ -29,6 +29,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.Repository
diff --git a/github/NotificationSubject.py b/github/NotificationSubject.py
index e970a171..46b70ff1 100644
--- a/github/NotificationSubject.py
+++ b/github/NotificationSubject.py
@@ -28,6 +28,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Organization.py b/github/Organization.py
index 258938ac..e9daa8af 100644
--- a/github/Organization.py
+++ b/github/Organization.py
@@ -41,6 +41,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
 import github.GithubObject
@@ -53,7 +54,8 @@ import github.Repository
 import github.Project
 import github.NamedUser
 
-import Consts
+from . import Consts
+import six
 
 
 class Organization(github.GithubObject.CompletableGithubObject):
@@ -319,7 +321,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param role: string
         :rtype: None
         """
-        assert role is github.GithubObject.NotSet or isinstance(role, (str, unicode)), role
+        assert role is github.GithubObject.NotSet or isinstance(role, (str, six.text_type)), role
         assert isinstance(member, github.NamedUser.NamedUser), member
         put_parameters = {}
         if role is not github.GithubObject.NotSet:
@@ -367,9 +369,9 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param active: bool
         :rtype: :class:`github.Hook.Hook`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         assert isinstance(config, dict), config
-        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in events), events
+        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in events), events
         assert active is github.GithubObject.NotSet or isinstance(active, bool), active
         post_parameters = {
             "name": name,
@@ -412,18 +414,18 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param allow_rebase_merge: bool
         :rtype: :class:`github.Repository.Repository`
         """
-        assert isinstance(name, (str, unicode)), name
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
-        assert homepage is github.GithubObject.NotSet or isinstance(homepage, (str, unicode)), homepage
+        assert isinstance(name, (str, six.text_type)), name
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
+        assert homepage is github.GithubObject.NotSet or isinstance(homepage, (str, six.text_type)), homepage
         assert private is github.GithubObject.NotSet or isinstance(private, bool), private
         assert has_issues is github.GithubObject.NotSet or isinstance(has_issues, bool), has_issues
         assert has_wiki is github.GithubObject.NotSet or isinstance(has_wiki, bool), has_wiki
         assert has_downloads is github.GithubObject.NotSet or isinstance(has_downloads, bool), has_downloads
         assert has_projects is github.GithubObject.NotSet or isinstance(has_projects, bool), has_projects
-        assert team_id is github.GithubObject.NotSet or isinstance(team_id, (int, long)), team_id
+        assert team_id is github.GithubObject.NotSet or isinstance(team_id, six.integer_types), team_id
         assert auto_init is github.GithubObject.NotSet or isinstance(auto_init, bool), auto_init
-        assert license_template is github.GithubObject.NotSet or isinstance(license_template, (str, unicode)), license_template
-        assert gitignore_template is github.GithubObject.NotSet or isinstance(gitignore_template, (str, unicode)), gitignore_template
+        assert license_template is github.GithubObject.NotSet or isinstance(license_template, (str, six.text_type)), license_template
+        assert gitignore_template is github.GithubObject.NotSet or isinstance(gitignore_template, (str, six.text_type)), gitignore_template
         assert allow_squash_merge is github.GithubObject.NotSet or isinstance(allow_squash_merge, bool), allow_squash_merge
         assert allow_merge_commit is github.GithubObject.NotSet or isinstance(allow_merge_commit, bool), allow_merge_commit
         assert allow_rebase_merge is github.GithubObject.NotSet or isinstance(allow_rebase_merge, bool), allow_rebase_merge
@@ -475,11 +477,11 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param description: string
         :rtype: :class:`github.Team.Team`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         assert repo_names is github.GithubObject.NotSet or all(isinstance(element, github.Repository.Repository) for element in repo_names), repo_names
-        assert permission is github.GithubObject.NotSet or isinstance(permission, (str, unicode)), permission
-        assert privacy is github.GithubObject.NotSet or isinstance(privacy, (str, unicode)), privacy
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
+        assert permission is github.GithubObject.NotSet or isinstance(permission, (str, six.text_type)), permission
+        assert privacy is github.GithubObject.NotSet or isinstance(privacy, (str, six.text_type)), privacy
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
         post_parameters = {
             "name": name,
         }
@@ -504,7 +506,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: None`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
             self.url + "/hooks/" + str(id)
@@ -522,13 +524,13 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param name: string
         :rtype: None
         """
-        assert billing_email is github.GithubObject.NotSet or isinstance(billing_email, (str, unicode)), billing_email
-        assert blog is github.GithubObject.NotSet or isinstance(blog, (str, unicode)), blog
-        assert company is github.GithubObject.NotSet or isinstance(company, (str, unicode)), company
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
-        assert email is github.GithubObject.NotSet or isinstance(email, (str, unicode)), email
-        assert location is github.GithubObject.NotSet or isinstance(location, (str, unicode)), location
-        assert name is github.GithubObject.NotSet or isinstance(name, (str, unicode)), name
+        assert billing_email is github.GithubObject.NotSet or isinstance(billing_email, (str, six.text_type)), billing_email
+        assert blog is github.GithubObject.NotSet or isinstance(blog, (str, six.text_type)), blog
+        assert company is github.GithubObject.NotSet or isinstance(company, (str, six.text_type)), company
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
+        assert email is github.GithubObject.NotSet or isinstance(email, (str, six.text_type)), email
+        assert location is github.GithubObject.NotSet or isinstance(location, (str, six.text_type)), location
+        assert name is github.GithubObject.NotSet or isinstance(name, (str, six.text_type)), name
         post_parameters = dict()
         if billing_email is not github.GithubObject.NotSet:
             post_parameters["billing_email"] = billing_email
@@ -561,10 +563,10 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param active: bool
         :rtype: :class:`github.Hook.Hook`
         """
-        assert isinstance(id, (int, long)), id
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(id, six.integer_types), id
+        assert isinstance(name, (str, six.text_type)), name
         assert isinstance(config, dict), config
-        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in events), events
+        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in events), events
         assert active is github.GithubObject.NotSet or isinstance(active, bool), active
         post_parameters = {
             "name": name,
@@ -599,7 +601,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.Hook.Hook`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/hooks/" + str(id)
@@ -630,11 +632,11 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param since: datetime.datetime
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Issue.Issue`
         """
-        assert filter is github.GithubObject.NotSet or isinstance(filter, (str, unicode)), filter
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
+        assert filter is github.GithubObject.NotSet or isinstance(filter, (str, six.text_type)), filter
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
         assert labels is github.GithubObject.NotSet or all(isinstance(element, github.Label.Label) for element in labels), labels
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
         url_parameters = dict()
         if filter is not github.GithubObject.NotSet:
@@ -665,9 +667,9 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
         """
         assert (filter_ is github.GithubObject.NotSet or
-                isinstance(filter_, (str, unicode))), filter_
+                isinstance(filter_, (str, six.text_type))), filter_
         assert (role is github.GithubObject.NotSet or
-                isinstance(role, (str, unicode))), role
+                isinstance(role, (str, six.text_type))), role
 
         url_parameters = {}
         if filter_ is not github.GithubObject.NotSet:
@@ -719,7 +721,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
         """
         assert (filter_ is github.GithubObject.NotSet or
-                isinstance(filter_, (str, unicode))), filter_
+                isinstance(filter_, (str, six.text_type))), filter_
 
         url_parameters = {}
         if filter_ is not github.GithubObject.NotSet:
@@ -761,7 +763,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param name: string
         :rtype: :class:`github.Repository.Repository`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             "/repos/" + self.login + "/" + name
@@ -776,9 +778,9 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param direction: string ('asc', desc')
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
         """
-        assert type is github.GithubObject.NotSet or isinstance(type, (str, unicode)), type
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert type is github.GithubObject.NotSet or isinstance(type, (str, six.text_type)), type
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
 
         url_parameters = dict()
         if type is not github.GithubObject.NotSet:
@@ -800,7 +802,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.Team.Team`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             "/teams/" + str(id)
@@ -813,7 +815,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :param slug: string
         :rtype: :class:`github.Team.Team`
         """
-        assert isinstance(slug, (str, unicode)), slug
+        assert isinstance(slug, (str, six.text_type)), slug
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/teams/" + slug
@@ -857,7 +859,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :rtype: None
         """
         assert user is github.GithubObject.NotSet or isinstance(user, github.NamedUser.NamedUser), user
-        assert email is github.GithubObject.NotSet or isinstance(email, (str, unicode)), email
+        assert email is github.GithubObject.NotSet or isinstance(email, (str, six.text_type)), email
         assert (email is github.GithubObject.NotSet) ^ (user is github.GithubObject.NotSet), "specify only one of email or user"
         parameters = {}
         if user is not github.GithubObject.NotSet:
@@ -865,7 +867,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         elif email is not github.GithubObject.NotSet:
             parameters["email"] = email
         if role is not github.GithubObject.NotSet:
-            assert isinstance(role, (str, unicode)), role
+            assert isinstance(role, (str, six.text_type)), role
             assert role in ['admin', 'direct_member', 'billing_manager']
             parameters["role"] = role
         if teams is not github.GithubObject.NotSet:
@@ -954,7 +956,7 @@ class Organization(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.Migration.Migration`
         """
         assert isinstance(repos, (list, tuple)), repos
-        assert all(isinstance(repo, (str, unicode)) for repo in repos), repos
+        assert all(isinstance(repo, (str, six.text_type)) for repo in repos), repos
         assert lock_repositories is github.GithubObject.NotSet or isinstance(lock_repositories, bool), lock_repositories
         assert exclude_attachments is github.GithubObject.NotSet or isinstance(exclude_attachments, bool), exclude_attachments
         post_parameters = {
diff --git a/github/PaginatedList.py b/github/PaginatedList.py
index 20c2ddf8..14d148b1 100644
--- a/github/PaginatedList.py
+++ b/github/PaginatedList.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import
+import six
 # -*- coding: utf-8 -*-
 
 ############################ Copyrights and license ############################
@@ -40,7 +42,7 @@
 try:
     from urllib.parse import parse_qs
 except ImportError:
-    from urlparse import parse_qs
+    from six.moves.urllib.parse import parse_qs
 
 
 class PaginatedListBase:
@@ -49,7 +51,7 @@ class PaginatedListBase:
 
     def __getitem__(self, index):
         assert isinstance(index, (int, slice))
-        if isinstance(index, (int, long)):
+        if isinstance(index, six.integer_types):
             self.__fetchToIndex(index)
             return self.__elements[index]
         else:
diff --git a/github/Path.py b/github/Path.py
index 615c0da1..7843b9f7 100644
--- a/github/Path.py
+++ b/github/Path.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Permissions.py b/github/Permissions.py
index 1438ee47..4a298e90 100644
--- a/github/Permissions.py
+++ b/github/Permissions.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Plan.py b/github/Plan.py
index a740afbb..22377bdb 100644
--- a/github/Plan.py
+++ b/github/Plan.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Project.py b/github/Project.py
index e5653dc6..cdbe9f96 100644
--- a/github/Project.py
+++ b/github/Project.py
@@ -22,10 +22,12 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.ProjectColumn
 
-import Consts
+from . import Consts
+import six
 
 
 class Project(github.GithubObject.CompletableGithubObject):
@@ -159,7 +161,7 @@ class Project(github.GithubObject.CompletableGithubObject):
         calls: `POST https://developer.github.com/v3/projects/columns/#create-a-project-column>`_
         :param name: string
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         post_parameters = {"name": name}
         import_header = {"Accept": Consts.mediaTypeProjectsPreview}
         headers, data = self._requester.requestJsonAndCheck(
diff --git a/github/ProjectCard.py b/github/ProjectCard.py
index 8b52f2c9..52d1e5a5 100644
--- a/github/ProjectCard.py
+++ b/github/ProjectCard.py
@@ -22,6 +22,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 # NOTE: There is currently no way to get cards "in triage" for a project.
diff --git a/github/ProjectColumn.py b/github/ProjectColumn.py
index 41a9658a..816b3fd9 100644
--- a/github/ProjectColumn.py
+++ b/github/ProjectColumn.py
@@ -22,11 +22,13 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.Project
 import github.ProjectCard
 
-import Consts
+from . import Consts
+import six
 
 
 class ProjectColumn(github.GithubObject.CompletableGithubObject):
@@ -99,7 +101,7 @@ class ProjectColumn(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.ProjectCard.ProjectCard`
         :param archived_state: string
         """
-        assert archived_state is github.GithubObject.NotSet or isinstance(archived_state, (str, unicode)), archived_state
+        assert archived_state is github.GithubObject.NotSet or isinstance(archived_state, (str, six.text_type)), archived_state
 
         url_parameters = dict()
         if archived_state is not github.GithubObject.NotSet:
@@ -123,14 +125,14 @@ class ProjectColumn(github.GithubObject.CompletableGithubObject):
         :param content_type: string
         """
         post_parameters = {}
-        if isinstance(note, (str, unicode)):
+        if isinstance(note, (str, six.text_type)):
             assert content_id is github.GithubObject.NotSet, content_id
             assert content_type is github.GithubObject.NotSet, content_type
             post_parameters = {"note": note}
         else:
             assert note is github.GithubObject.NotSet, note
             assert isinstance(content_id, int), content_id
-            assert isinstance(content_type, (str, unicode)), content_type
+            assert isinstance(content_type, (str, six.text_type)), content_type
             post_parameters = {"content_id": content_id,
                                "content_type": content_type}
 
diff --git a/github/PullRequest.py b/github/PullRequest.py
index 82073b31..590fc07f 100644
--- a/github/PullRequest.py
+++ b/github/PullRequest.py
@@ -42,8 +42,9 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
-import urllib
+import six.moves.urllib.request, six.moves.urllib.parse, six.moves.urllib.error
 import github.GithubObject
 import github.PaginatedList
 
@@ -56,7 +57,8 @@ import github.IssueComment
 import github.Commit
 import github.PullRequestReview
 
-import Consts
+from . import Consts
+import six
 
 
 class PullRequest(github.GithubObject.CompletableGithubObject):
@@ -386,10 +388,10 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param position: integer
         :rtype: :class:`github.PullRequestComment.PullRequestComment`
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         assert isinstance(commit_id, github.Commit.Commit), commit_id
-        assert isinstance(path, (str, unicode)), path
-        assert isinstance(position, (int, long)), position
+        assert isinstance(path, (str, six.text_type)), path
+        assert isinstance(position, six.integer_types), position
         post_parameters = {
             "body": body,
             "commit_id": commit_id._identity,
@@ -409,7 +411,7 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param body: string
         :rtype: :class:`github.IssueComment.IssueComment`
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "body": body,
         }
@@ -459,10 +461,10 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         """
         post_parameters = dict()
         if reviewers is not github.GithubObject.NotSet:
-            assert all(isinstance(element, (str, unicode)) for element in reviewers), reviewers
+            assert all(isinstance(element, (str, six.text_type)) for element in reviewers), reviewers
             post_parameters["reviewers"] = reviewers
         if team_reviewers is not github.GithubObject.NotSet:
-            assert all(isinstance(element, (str, unicode)) for element in team_reviewers), team_reviewers
+            assert all(isinstance(element, (str, six.text_type)) for element in team_reviewers), team_reviewers
             post_parameters["team_reviewers"] = team_reviewers
         headers, data = self._requester.requestJsonAndCheck(
             "POST",
@@ -479,10 +481,10 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         """
         post_parameters = dict()
         if reviewers is not github.GithubObject.NotSet:
-            assert all(isinstance(element, (str, unicode)) for element in reviewers), reviewers
+            assert all(isinstance(element, (str, six.text_type)) for element in reviewers), reviewers
             post_parameters["reviewers"] = reviewers
         if team_reviewers is not github.GithubObject.NotSet:
-            assert all(isinstance(element, (str, unicode)) for element in team_reviewers), team_reviewers
+            assert all(isinstance(element, (str, six.text_type)) for element in team_reviewers), team_reviewers
             post_parameters["team_reviewers"] = team_reviewers
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
@@ -499,10 +501,10 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param base: string
         :rtype: None
         """
-        assert title is github.GithubObject.NotSet or isinstance(title, (str, unicode)), title
-        assert body is github.GithubObject.NotSet or isinstance(body, (str, unicode)), body
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
-        assert base is github.GithubObject.NotSet or isinstance(base, (str, unicode)), base
+        assert title is github.GithubObject.NotSet or isinstance(title, (str, six.text_type)), title
+        assert body is github.GithubObject.NotSet or isinstance(body, (str, six.text_type)), body
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
+        assert base is github.GithubObject.NotSet or isinstance(base, (str, six.text_type)), base
         post_parameters = dict()
         if title is not github.GithubObject.NotSet:
             post_parameters["title"] = title
@@ -533,7 +535,7 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.PullRequestComment.PullRequestComment`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self._parentUrl(self.url) + "/comments/" + str(id)
@@ -572,7 +574,7 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.PullRequestComment.PullRequestComment`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         return github.PaginatedList.PaginatedList(
             github.PullRequestComment.PullRequestComment,
             self._requester,
@@ -610,7 +612,7 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.IssueComment.IssueComment`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self._parentUrl(self.issue_url) + "/comments/" + str(id)
@@ -648,7 +650,7 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.PullRequestReview.PullRequestReview`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/reviews/" + str(id),
@@ -707,7 +709,7 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param label: :class:`github.Label.Label` or string
         :rtype: None
         """
-        assert all(isinstance(element, (github.Label.Label, str, unicode)) for element in labels), labels
+        assert all(isinstance(element, (github.Label.Label, str, six.text_type)) for element in labels), labels
         post_parameters = [label.name if isinstance(label, github.Label.Label) else label for label in labels]
         headers, data = self._requester.requestJsonAndCheck(
             "POST",
@@ -731,11 +733,11 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param label: :class:`github.Label.Label` or string
         :rtype: None
         """
-        assert isinstance(label, (github.Label.Label, str, unicode)), label
+        assert isinstance(label, (github.Label.Label, str, six.text_type)), label
         if isinstance(label, github.Label.Label):
             label = label._identity
         else:
-            label = urllib.quote(label)
+            label = six.moves.urllib.parse.quote(label)
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
             self.issue_url + "/labels/" + label
@@ -747,7 +749,7 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param labels: list of :class:`github.Label.Label` or strings
         :rtype: None
         """
-        assert all(isinstance(element, (github.Label.Label, str, unicode)) for element in labels), labels
+        assert all(isinstance(element, (github.Label.Label, str, six.text_type)) for element in labels), labels
         post_parameters = [label.name if isinstance(label, github.Label.Label) else label for label in labels]
         headers, data = self._requester.requestJsonAndCheck(
             "PUT",
@@ -772,10 +774,10 @@ class PullRequest(github.GithubObject.CompletableGithubObject):
         :param commit_message: string
         :rtype: :class:`github.PullRequestMergeStatus.PullRequestMergeStatus`
         """
-        assert commit_message is github.GithubObject.NotSet or isinstance(commit_message, (str, unicode)), commit_message
-        assert commit_title is github.GithubObject.NotSet or isinstance(commit_title, (str, unicode)), commit_title
-        assert merge_method is github.GithubObject.NotSet or isinstance(merge_method, (str, unicode)), merge_method
-        assert sha is github.GithubObject.NotSet or isinstance(sha, (str, unicode)), sha
+        assert commit_message is github.GithubObject.NotSet or isinstance(commit_message, (str, six.text_type)), commit_message
+        assert commit_title is github.GithubObject.NotSet or isinstance(commit_title, (str, six.text_type)), commit_title
+        assert merge_method is github.GithubObject.NotSet or isinstance(merge_method, (str, six.text_type)), merge_method
+        assert sha is github.GithubObject.NotSet or isinstance(sha, (str, six.text_type)), sha
         post_parameters = dict()
         if commit_message is not github.GithubObject.NotSet:
             post_parameters["commit_message"] = commit_message
diff --git a/github/PullRequestComment.py b/github/PullRequestComment.py
index e8636114..edd4a54e 100644
--- a/github/PullRequestComment.py
+++ b/github/PullRequestComment.py
@@ -34,10 +34,12 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.NamedUser
 
-import Consts
+from . import Consts
+import six
 
 
 class PullRequestComment(github.GithubObject.CompletableGithubObject):
@@ -184,7 +186,7 @@ class PullRequestComment(github.GithubObject.CompletableGithubObject):
         :param body: string
         :rtype: None
         """
-        assert isinstance(body, (str, unicode)), body
+        assert isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "body": body,
         }
@@ -216,7 +218,7 @@ class PullRequestComment(github.GithubObject.CompletableGithubObject):
         :param reaction_type: string
         :rtype: :class:`github.Reaction.Reaction`
         """
-        assert isinstance(reaction_type, (str, unicode)), "reaction type should be a string"
+        assert isinstance(reaction_type, (str, six.text_type)), "reaction type should be a string"
         assert reaction_type in ["+1", "-1", "laugh", "confused", "heart", "hooray"], \
             "Invalid reaction type (https://developer.github.com/v3/reactions/#reaction-types)"
 
diff --git a/github/PullRequestMergeStatus.py b/github/PullRequestMergeStatus.py
index add34390..5cf0a53f 100644
--- a/github/PullRequestMergeStatus.py
+++ b/github/PullRequestMergeStatus.py
@@ -31,6 +31,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/PullRequestPart.py b/github/PullRequestPart.py
index e68ba151..3e4a4da1 100644
--- a/github/PullRequestPart.py
+++ b/github/PullRequestPart.py
@@ -30,6 +30,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.Repository
diff --git a/github/PullRequestReview.py b/github/PullRequestReview.py
index afde6f6a..d48b3b1e 100644
--- a/github/PullRequestReview.py
+++ b/github/PullRequestReview.py
@@ -26,9 +26,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
+import six
 
 
 class PullRequestReview(github.GithubObject.CompletableGithubObject):
@@ -116,7 +118,7 @@ class PullRequestReview(github.GithubObject.CompletableGithubObject):
         :calls: `PUT /repos/:owner/:repo/pulls/:number/reviews/:review_id/dismissals <https://developer.github.com/v3/pulls/reviews/>`_
         :rtype: None
         """
-        assert isinstance(message, (str, unicode)), message
+        assert isinstance(message, (str, six.text_type)), message
         post_parameters = {'message': message}
         headers, data = self._requester.requestJsonAndCheck(
             "PUT",
diff --git a/github/Rate.py b/github/Rate.py
index e9fbe500..22ed3e8d 100644
--- a/github/Rate.py
+++ b/github/Rate.py
@@ -27,6 +27,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/RateLimit.py b/github/RateLimit.py
index 8fc78e40..68d928fb 100644
--- a/github/RateLimit.py
+++ b/github/RateLimit.py
@@ -27,6 +27,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.Rate
 
diff --git a/github/Reaction.py b/github/Reaction.py
index 994ef755..2f916e2d 100644
--- a/github/Reaction.py
+++ b/github/Reaction.py
@@ -24,10 +24,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.NamedUser
 
-import Consts
+from . import Consts
 
 
 class Reaction(github.GithubObject.CompletableGithubObject):
diff --git a/github/Referrer.py b/github/Referrer.py
index eb14931b..9a03dd9e 100644
--- a/github/Referrer.py
+++ b/github/Referrer.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Repository.py b/github/Repository.py
index f8fb9ee8..e2e1291f 100644
--- a/github/Repository.py
+++ b/github/Repository.py
@@ -85,8 +85,9 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import sys
-import urllib
+import six.moves.urllib.request, six.moves.urllib.parse, six.moves.urllib.error
 import datetime
 from base64 import b64encode
 
@@ -134,7 +135,8 @@ import github.Path
 import github.Clones
 import github.View
 
-import Consts
+from . import Consts
+import six
 
 atLeastPython3 = sys.hexversion >= 0x03000000
 
@@ -778,8 +780,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param permission: string 'pull', 'push' or 'admin'
         :rtype: None
         """
-        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, unicode)), collaborator
-        assert permission is github.GithubObject.NotSet or isinstance(permission, (str, unicode)), permission
+        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, six.text_type)), collaborator
+        assert permission is github.GithubObject.NotSet or isinstance(permission, (str, six.text_type)), permission
 
         if isinstance(collaborator, github.NamedUser.NamedUser):
             collaborator = collaborator._identity
@@ -805,7 +807,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param collaborator: string or :class:`github.NamedUser.NamedUser`
         :rtype: string
         """
-        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, unicode)), collaborator
+        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, six.text_type)), collaborator
         if isinstance(collaborator, github.NamedUser.NamedUser):
             collaborator = collaborator._identity
         headers, data = self._requester.requestJsonAndCheck(
@@ -845,8 +847,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param head: string
         :rtype: :class:`github.Comparison.Comparison`
         """
-        assert isinstance(base, (str, unicode)), base
-        assert isinstance(head, (str, unicode)), head
+        assert isinstance(base, (str, six.text_type)), base
+        assert isinstance(head, (str, six.text_type)), head
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/compare/" + base + "..." + head
@@ -860,8 +862,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param encoding: string
         :rtype: :class:`github.GitBlob.GitBlob`
         """
-        assert isinstance(content, (str, unicode)), content
-        assert isinstance(encoding, (str, unicode)), encoding
+        assert isinstance(content, (str, six.text_type)), content
+        assert isinstance(encoding, (str, six.text_type)), encoding
         post_parameters = {
             "content": content,
             "encoding": encoding,
@@ -883,7 +885,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param committer: :class:`github.InputGitAuthor.InputGitAuthor`
         :rtype: :class:`github.GitCommit.GitCommit`
         """
-        assert isinstance(message, (str, unicode)), message
+        assert isinstance(message, (str, six.text_type)), message
         assert isinstance(tree, github.GitTree.GitTree), tree
         assert all(isinstance(element, github.GitCommit.GitCommit) for element in parents), parents
         assert author is github.GithubObject.NotSet or isinstance(author, github.InputGitAuthor), author
@@ -911,8 +913,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param sha: string
         :rtype: :class:`github.GitRef.GitRef`
         """
-        assert isinstance(ref, (str, unicode)), ref
-        assert isinstance(sha, (str, unicode)), sha
+        assert isinstance(ref, (str, six.text_type)), ref
+        assert isinstance(sha, (str, six.text_type)), sha
         post_parameters = {
             "ref": ref,
             "sha": sha,
@@ -939,12 +941,12 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param target_commitish: string or :class:`github.Branch.Branch` or :class:`github.Commit.Commit` or :class:`github.GitCommit.GitCommit`
         :rtype: :class:`github.GitRelease.GitRelease`
         """
-        assert isinstance(tag, (str, unicode)), tag
-        assert isinstance(name, (str, unicode)), name
-        assert isinstance(message, (str, unicode)), message
+        assert isinstance(tag, (str, six.text_type)), tag
+        assert isinstance(name, (str, six.text_type)), name
+        assert isinstance(message, (str, six.text_type)), message
         assert isinstance(draft, bool), draft
         assert isinstance(prerelease, bool), prerelease
-        assert target_commitish is github.GithubObject.NotSet or isinstance(target_commitish, (str, unicode, github.Branch.Branch, github.Commit.Commit, github.GitCommit.GitCommit)), target_commitish
+        assert target_commitish is github.GithubObject.NotSet or isinstance(target_commitish, (str, six.text_type, github.Branch.Branch, github.Commit.Commit, github.GitCommit.GitCommit)), target_commitish
         post_parameters = {
             "tag_name": tag,
             "name": name,
@@ -952,7 +954,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
             "draft": draft,
             "prerelease": prerelease,
         }
-        if isinstance(target_commitish, (str, unicode)):
+        if isinstance(target_commitish, (str, six.text_type)):
             post_parameters["target_commitish"] = target_commitish
         elif isinstance(target_commitish, github.Branch.Branch):
             post_parameters["target_commitish"] = target_commitish.name
@@ -975,10 +977,10 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param tagger: :class:`github.InputGitAuthor.InputGitAuthor`
         :rtype: :class:`github.GitTag.GitTag`
         """
-        assert isinstance(tag, (str, unicode)), tag
-        assert isinstance(message, (str, unicode)), message
-        assert isinstance(object, (str, unicode)), object
-        assert isinstance(type, (str, unicode)), type
+        assert isinstance(tag, (str, six.text_type)), tag
+        assert isinstance(message, (str, six.text_type)), message
+        assert isinstance(object, (str, six.text_type)), object
+        assert isinstance(type, (str, six.text_type)), type
         assert tagger is github.GithubObject.NotSet or isinstance(tagger, github.InputGitAuthor), tagger
         post_parameters = {
             "tag": tag,
@@ -1025,9 +1027,9 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param active: bool
         :rtype: :class:`github.Hook.Hook`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         assert isinstance(config, dict), config
-        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, unicode)) for element in events), events
+        assert events is github.GithubObject.NotSet or all(isinstance(element, (str, six.text_type)) for element in events), events
         assert active is github.GithubObject.NotSet or isinstance(active, bool), active
         post_parameters = {
             "name": name,
@@ -1055,12 +1057,12 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param labels: list of :class:`github.Label.Label`
         :rtype: :class:`github.Issue.Issue`
         """
-        assert isinstance(title, (str, unicode)), title
-        assert body is github.GithubObject.NotSet or isinstance(body, (str, unicode)), body
-        assert assignee is github.GithubObject.NotSet or isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, unicode)), assignee
-        assert assignees is github.GithubObject.NotSet or all(isinstance(element, github.NamedUser.NamedUser) or isinstance(element, (str, unicode)) for element in assignees), assignees
+        assert isinstance(title, (str, six.text_type)), title
+        assert body is github.GithubObject.NotSet or isinstance(body, (str, six.text_type)), body
+        assert assignee is github.GithubObject.NotSet or isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, six.text_type)), assignee
+        assert assignees is github.GithubObject.NotSet or all(isinstance(element, github.NamedUser.NamedUser) or isinstance(element, (str, six.text_type)) for element in assignees), assignees
         assert milestone is github.GithubObject.NotSet or isinstance(milestone, github.Milestone.Milestone), milestone
-        assert labels is github.GithubObject.NotSet or all(isinstance(element, github.Label.Label) or isinstance(element, (str, unicode)) for element in labels), labels
+        assert labels is github.GithubObject.NotSet or all(isinstance(element, github.Label.Label) or isinstance(element, (str, six.text_type)) for element in labels), labels
 
         post_parameters = {
             "title": title,
@@ -1068,7 +1070,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         if body is not github.GithubObject.NotSet:
             post_parameters["body"] = body
         if assignee is not github.GithubObject.NotSet:
-            if isinstance(assignee, (str, unicode)):
+            if isinstance(assignee, (str, six.text_type)):
                 post_parameters["assignee"] = assignee
             else:
                 post_parameters["assignee"] = assignee._identity
@@ -1093,8 +1095,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param read_only: bool
         :rtype: :class:`github.RepositoryKey.RepositoryKey`
         """
-        assert isinstance(title, (str, unicode)), title
-        assert isinstance(key, (str, unicode)), key
+        assert isinstance(title, (str, six.text_type)), title
+        assert isinstance(key, (str, six.text_type)), key
         assert isinstance(read_only, bool), read_only
         post_parameters = {
             "title": title,
@@ -1116,9 +1118,9 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param description: string
         :rtype: :class:`github.Label.Label`
         """
-        assert isinstance(name, (str, unicode)), name
-        assert isinstance(color, (str, unicode)), color
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
+        assert isinstance(name, (str, six.text_type)), name
+        assert isinstance(color, (str, six.text_type)), color
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
         post_parameters = {
             "name": name,
             "color": color,
@@ -1142,9 +1144,9 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param due_on: datetime
         :rtype: :class:`github.Milestone.Milestone`
         """
-        assert isinstance(title, (str, unicode)), title
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
+        assert isinstance(title, (str, six.text_type)), title
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
         assert due_on is github.GithubObject.NotSet or isinstance(due_on, (datetime.datetime, datetime.date)), due_on
         post_parameters = {
             "title": title,
@@ -1171,8 +1173,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param name: string
         :param body: string
         """
-        assert isinstance(name, (str, unicode)), name
-        assert body is github.GithubObject.NotSet or isinstance(body, (str, unicode)), body
+        assert isinstance(name, (str, six.text_type)), name
+        assert body is github.GithubObject.NotSet or isinstance(body, (str, six.text_type)), body
         post_parameters = {
             "name": name,
             "body": body,
@@ -1205,10 +1207,10 @@ class Repository(github.GithubObject.CompletableGithubObject):
             return self.__create_pull_2(*args, **kwds)
 
     def __create_pull_1(self, title, body, base, head, maintainer_can_modify=github.GithubObject.NotSet):
-        assert isinstance(title, (str, unicode)), title
-        assert isinstance(body, (str, unicode)), body
-        assert isinstance(base, (str, unicode)), base
-        assert isinstance(head, (str, unicode)), head
+        assert isinstance(title, (str, six.text_type)), title
+        assert isinstance(body, (str, six.text_type)), body
+        assert isinstance(base, (str, six.text_type)), base
+        assert isinstance(head, (str, six.text_type)), head
         assert maintainer_can_modify is github.GithubObject.NotSet or isinstance(maintainer_can_modify, bool), maintainer_can_modify
         if maintainer_can_modify is not github.GithubObject.NotSet:
             return self.__create_pull(title=title, body=body, base=base, head=head, maintainer_can_modify=maintainer_can_modify)
@@ -1217,8 +1219,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
 
     def __create_pull_2(self, issue, base, head):
         assert isinstance(issue, github.Issue.Issue), issue
-        assert isinstance(base, (str, unicode)), base
-        assert isinstance(head, (str, unicode)), head
+        assert isinstance(base, (str, six.text_type)), base
+        assert isinstance(head, (str, six.text_type)), head
         return self.__create_pull(issue=issue._identity, base=base, head=head)
 
     def __create_pull(self, **kwds):
@@ -1239,10 +1241,10 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param vcs_password: string
         :rtype: :class:`github.SourceImport.SourceImport`
         """
-        assert isinstance(vcs, (str, unicode)), vcs
-        assert isinstance(vcs_url, (str, unicode)), vcs_url
-        assert vcs_username is github.GithubObject.NotSet or isinstance(vcs_username, (str, unicode)), vcs_username
-        assert vcs_password is github.GithubObject.NotSet or isinstance(vcs_password, (str, unicode)), vcs_password
+        assert isinstance(vcs, (str, six.text_type)), vcs
+        assert isinstance(vcs_url, (str, six.text_type)), vcs_url
+        assert vcs_username is github.GithubObject.NotSet or isinstance(vcs_username, (str, six.text_type)), vcs_username
+        assert vcs_password is github.GithubObject.NotSet or isinstance(vcs_password, (str, six.text_type)), vcs_password
         put_parameters = {
             "vcs": vcs,
             "vcs_url": vcs_url
@@ -1295,15 +1297,15 @@ class Repository(github.GithubObject.CompletableGithubObject):
         """
         if name is None:
             name = self.name
-        assert isinstance(name, (str, unicode)), name
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
-        assert homepage is github.GithubObject.NotSet or isinstance(homepage, (str, unicode)), homepage
+        assert isinstance(name, (str, six.text_type)), name
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
+        assert homepage is github.GithubObject.NotSet or isinstance(homepage, (str, six.text_type)), homepage
         assert private is github.GithubObject.NotSet or isinstance(private, bool), private
         assert has_issues is github.GithubObject.NotSet or isinstance(has_issues, bool), has_issues
         assert has_projects is github.GithubObject.NotSet or isinstance(has_projects, bool), has_projects
         assert has_wiki is github.GithubObject.NotSet or isinstance(has_wiki, bool), has_wiki
         assert has_downloads is github.GithubObject.NotSet or isinstance(has_downloads, bool), has_downloads
-        assert default_branch is github.GithubObject.NotSet or isinstance(default_branch, (str, unicode)), default_branch
+        assert default_branch is github.GithubObject.NotSet or isinstance(default_branch, (str, six.text_type)), default_branch
         assert allow_squash_merge is github.GithubObject.NotSet or isinstance(allow_squash_merge, bool), allow_squash_merge
         assert allow_merge_commit is github.GithubObject.NotSet or isinstance(allow_merge_commit, bool), allow_merge_commit
         assert allow_rebase_merge is github.GithubObject.NotSet or isinstance(allow_rebase_merge, bool), allow_rebase_merge
@@ -1349,8 +1351,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param ref: string
         :rtype: string
         """
-        assert isinstance(archive_format, (str, unicode)), archive_format
-        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, unicode)), ref
+        assert isinstance(archive_format, (str, six.text_type)), archive_format
+        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, six.text_type)), ref
         url = self.url + "/" + archive_format
         if ref is not github.GithubObject.NotSet:
             url += "/" + ref
@@ -1378,7 +1380,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param branch: string
         :rtype: :class:`github.Branch.Branch`
         """
-        assert isinstance(branch, (str, unicode)), branch
+        assert isinstance(branch, (str, six.text_type)), branch
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/branches/" + branch
@@ -1425,7 +1427,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.CommitComment.CommitComment`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/comments/" + str(id)
@@ -1450,7 +1452,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param sha: string
         :rtype: :class:`github.Commit.Commit`
         """
-        assert isinstance(sha, (str, unicode)), sha
+        assert isinstance(sha, (str, six.text_type)), sha
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/commits/" + sha
@@ -1467,11 +1469,11 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param author: string or :class:`github.NamedUser.NamedUser` or :class:`github.AuthenticatedUser.AuthenticatedUser`
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Commit.Commit`
         """
-        assert sha is github.GithubObject.NotSet or isinstance(sha, (str, unicode)), sha
-        assert path is github.GithubObject.NotSet or isinstance(path, (str, unicode)), path
+        assert sha is github.GithubObject.NotSet or isinstance(sha, (str, six.text_type)), sha
+        assert path is github.GithubObject.NotSet or isinstance(path, (str, six.text_type)), path
         assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
         assert until is github.GithubObject.NotSet or isinstance(until, datetime.datetime), until
-        assert author is github.GithubObject.NotSet or isinstance(author, (str, unicode, github.NamedUser.NamedUser, github.AuthenticatedUser.AuthenticatedUser)), author
+        assert author is github.GithubObject.NotSet or isinstance(author, (str, six.text_type, github.NamedUser.NamedUser, github.AuthenticatedUser.AuthenticatedUser)), author
         url_parameters = dict()
         if sha is not github.GithubObject.NotSet:
             url_parameters["sha"] = sha
@@ -1500,8 +1502,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param ref: string
         :rtype: :class:`github.ContentFile.ContentFile`
         """
-        assert isinstance(path, (str, unicode)), path
-        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, unicode)), ref
+        assert isinstance(path, (str, six.text_type)), path
+        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, six.text_type)), ref
         # Path of '/' should be the empty string.
         if path == '/':
             path = ''
@@ -1510,7 +1512,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
             url_parameters["ref"] = ref
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
-            self.url + "/contents/" + urllib.quote(path),
+            self.url + "/contents/" + six.moves.urllib.parse.quote(path),
             parameters=url_parameters
         )
         if isinstance(data, list):
@@ -1556,7 +1558,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param per: string, must be one of day or week, day by default
         :rtype: None or list of :class:`github.View.View`
         """
-        assert per is github.GithubObject.NotSet or (isinstance(per, (str, unicode)) and (per == "day" or per == "week")), "per must be day or week, day by default"
+        assert per is github.GithubObject.NotSet or (isinstance(per, (str, six.text_type)) and (per == "day" or per == "week")), "per must be day or week, day by default"
         url_parameters = dict()
         if per is not github.GithubObject.NotSet:
             url_parameters["per"] = per
@@ -1578,7 +1580,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param per: string, must be one of day or week, day by default
         :rtype: None or list of :class:`github.Clone.Clone`
         """
-        assert per is github.GithubObject.NotSet or (isinstance(per, (str, unicode)) and (per == "day" or per == "week")), "per must be day or week, day by default"
+        assert per is github.GithubObject.NotSet or (isinstance(per, (str, six.text_type)) and (per == "day" or per == "week")), "per must be day or week, day by default"
         url_parameters = dict()
         if per is not github.GithubObject.NotSet:
             url_parameters["per"] = per
@@ -1630,14 +1632,14 @@ class Repository(github.GithubObject.CompletableGithubObject):
             'content': :class:`ContentFile <github.ContentFile.ContentFile>`:,
             'commit': :class:`Commit <github.Commit.Commit>`}
         """
-        assert isinstance(path, (str, unicode)),                   \
+        assert isinstance(path, (str, six.text_type)),                   \
             'path must be str/unicode object'
-        assert isinstance(message, (str, unicode)),                \
+        assert isinstance(message, (str, six.text_type)),                \
             'message must be str/unicode object'
-        assert isinstance(content, (str, unicode, bytes)),         \
+        assert isinstance(content, (str, six.text_type, bytes)),         \
             'content must be a str/unicode object'
         assert branch is github.GithubObject.NotSet                \
-            or isinstance(branch, (str, unicode)),                 \
+            or isinstance(branch, (str, six.text_type)),                 \
             'branch must be a str/unicode object'
         assert author is github.GithubObject.NotSet                \
             or isinstance(author, github.InputGitAuthor),          \
@@ -1651,7 +1653,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
                 content = content.encode('utf-8')
             content = b64encode(content).decode('utf-8')
         else:
-            if isinstance(content, unicode):
+            if isinstance(content, six.text_type):
                 content = content.encode('utf-8')
             content = b64encode(content)
         put_parameters = {'message': message, 'content': content}
@@ -1665,7 +1667,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
 
         headers, data = self._requester.requestJsonAndCheck(
             "PUT",
-            self.url + "/contents/" + urllib.quote(path),
+            self.url + "/contents/" + six.moves.urllib.parse.quote(path),
             input=put_parameters
         )
 
@@ -1690,16 +1692,16 @@ class Repository(github.GithubObject.CompletableGithubObject):
             'content': :class:`ContentFile <github.ContentFile.ContentFile>`:,
             'commit': :class:`Commit <github.Commit.Commit>`}
         """
-        assert isinstance(path, (str, unicode)),                   \
+        assert isinstance(path, (str, six.text_type)),                   \
             'path must be str/unicode object'
-        assert isinstance(message, (str, unicode)),                \
+        assert isinstance(message, (str, six.text_type)),                \
             'message must be str/unicode object'
-        assert isinstance(content, (str, unicode, bytes)),         \
+        assert isinstance(content, (str, six.text_type, bytes)),         \
             'content must be a str/unicode object'
-        assert isinstance(sha, (str, unicode)),                    \
+        assert isinstance(sha, (str, six.text_type)),                    \
             'sha must be a str/unicode object'
         assert branch is github.GithubObject.NotSet                \
-            or isinstance(branch, (str, unicode)),                 \
+            or isinstance(branch, (str, six.text_type)),                 \
             'branch must be a str/unicode object'
         assert author is github.GithubObject.NotSet                \
             or isinstance(author, github.InputGitAuthor),          \
@@ -1713,7 +1715,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
                 content = content.encode('utf-8')
             content = b64encode(content).decode('utf-8')
         else:
-            if isinstance(content, unicode):
+            if isinstance(content, six.text_type):
                 content = content.encode('utf-8')
             content = b64encode(content)
 
@@ -1729,7 +1731,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
 
         headers, data = self._requester.requestJsonAndCheck(
             "PUT",
-            self.url + "/contents/" + urllib.quote(path),
+            self.url + "/contents/" + six.moves.urllib.parse.quote(path),
             input=put_parameters
         )
 
@@ -1753,14 +1755,14 @@ class Repository(github.GithubObject.CompletableGithubObject):
             'content': :class:`null <github.GithubObject.NotSet>`:,
             'commit': :class:`Commit <github.Commit.Commit>`}
         """
-        assert isinstance(path, (str, unicode)),                   \
+        assert isinstance(path, (str, six.text_type)),                   \
             'path must be str/unicode object'
-        assert isinstance(message, (str, unicode)),                \
+        assert isinstance(message, (str, six.text_type)),                \
             'message must be str/unicode object'
-        assert isinstance(sha, (str, unicode)),                    \
+        assert isinstance(sha, (str, six.text_type)),                    \
             'sha must be a str/unicode object'
         assert branch is github.GithubObject.NotSet                \
-            or isinstance(branch, (str, unicode)),                 \
+            or isinstance(branch, (str, six.text_type)),                 \
             'branch must be a str/unicode object'
         assert author is github.GithubObject.NotSet                \
             or isinstance(author, github.InputGitAuthor),          \
@@ -1779,7 +1781,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
 
         headers, data = self._requester.requestJsonAndCheck(
             "DELETE",
-            self.url + "/contents/" + urllib.quote(path),
+            self.url + "/contents/" + six.moves.urllib.parse.quote(path),
             input=url_parameters
         )
 
@@ -1793,14 +1795,14 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param ref: string
         :rtype: list of :class:`github.ContentFile.ContentFile`
         """
-        assert isinstance(path, (str, unicode)), path
-        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, unicode)), ref
+        assert isinstance(path, (str, six.text_type)), path
+        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, six.text_type)), ref
         url_parameters = dict()
         if ref is not github.GithubObject.NotSet:
             url_parameters["ref"] = ref
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
-            self.url + "/contents/" + urllib.quote(path),
+            self.url + "/contents/" + six.moves.urllib.parse.quote(path),
             parameters=url_parameters
         )
 
@@ -1840,7 +1842,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.Download.Download`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/downloads/" + str(id)
@@ -1889,7 +1891,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param sha: string
         :rtype: :class:`github.GitBlob.GitBlob`
         """
-        assert isinstance(sha, (str, unicode)), sha
+        assert isinstance(sha, (str, six.text_type)), sha
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/git/blobs/" + sha
@@ -1902,7 +1904,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param sha: string
         :rtype: :class:`github.GitCommit.GitCommit`
         """
-        assert isinstance(sha, (str, unicode)), sha
+        assert isinstance(sha, (str, six.text_type)), sha
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/git/commits/" + sha
@@ -1918,7 +1920,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         prefix = "/git/refs/"
         if not self._requester.FIX_REPO_GET_GIT_REF:
             prefix = "/git/"
-        assert isinstance(ref, (str, unicode)), ref
+        assert isinstance(ref, (str, six.text_type)), ref
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + prefix + ref
@@ -1943,7 +1945,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param sha: string
         :rtype: :class:`github.GitTag.GitTag`
         """
-        assert isinstance(sha, (str, unicode)), sha
+        assert isinstance(sha, (str, six.text_type)), sha
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/git/tags/" + sha
@@ -1957,7 +1959,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param recursive: bool
         :rtype: :class:`github.GitTree.GitTree`
         """
-        assert isinstance(sha, (str, unicode)), sha
+        assert isinstance(sha, (str, six.text_type)), sha
         assert recursive is github.GithubObject.NotSet or isinstance(recursive, bool), recursive
         url_parameters = dict()
         if recursive is not github.GithubObject.NotSet and recursive:
@@ -1976,7 +1978,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.Hook.Hook`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/hooks/" + str(id)
@@ -2001,7 +2003,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param number: integer
         :rtype: :class:`github.Issue.Issue`
         """
-        assert isinstance(number, (int, long)), number
+        assert isinstance(number, six.integer_types), number
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/issues/" + str(number)
@@ -2023,24 +2025,24 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Issue.Issue`
         """
         assert milestone is github.GithubObject.NotSet or milestone == "*" or milestone == "none" or isinstance(milestone, github.Milestone.Milestone), milestone
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
-        assert assignee is github.GithubObject.NotSet or isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, unicode)), assignee
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
+        assert assignee is github.GithubObject.NotSet or isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, six.text_type)), assignee
         assert mentioned is github.GithubObject.NotSet or isinstance(mentioned, github.NamedUser.NamedUser), mentioned
         assert labels is github.GithubObject.NotSet or all(isinstance(element, github.Label.Label) for element in labels), labels
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
-        assert creator is github.GithubObject.NotSet or isinstance(creator, github.NamedUser.NamedUser) or isinstance(creator, (str, unicode)), creator
+        assert creator is github.GithubObject.NotSet or isinstance(creator, github.NamedUser.NamedUser) or isinstance(creator, (str, six.text_type)), creator
         url_parameters = dict()
         if milestone is not github.GithubObject.NotSet:
-            if isinstance(milestone, (str, unicode)):
+            if isinstance(milestone, (str, six.text_type)):
                 url_parameters["milestone"] = milestone
             else:
                 url_parameters["milestone"] = milestone._identity
         if state is not github.GithubObject.NotSet:
             url_parameters["state"] = state
         if assignee is not github.GithubObject.NotSet:
-            if isinstance(assignee, (str, unicode)):
+            if isinstance(assignee, (str, six.text_type)):
                 url_parameters["assignee"] = assignee
             else:
                 url_parameters["assignee"] = assignee._identity
@@ -2055,7 +2057,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         if since is not github.GithubObject.NotSet:
             url_parameters["since"] = since.strftime("%Y-%m-%dT%H:%M:%SZ")
         if creator is not github.GithubObject.NotSet:
-            if isinstance(creator, (str, unicode)):
+            if isinstance(creator, (str, six.text_type)):
                 url_parameters["creator"] = creator
             else:
                 url_parameters["creator"] = creator._identity
@@ -2074,8 +2076,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param since: datetime.datetime
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.IssueComment.IssueComment`
         """
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
         url_parameters = dict()
         if sort is not github.GithubObject.NotSet:
@@ -2097,7 +2099,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.IssueEvent.IssueEvent`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/issues/events/" + str(id),
@@ -2124,7 +2126,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param id: integer
         :rtype: :class:`github.RepositoryKey.RepositoryKey`
         """
-        assert isinstance(id, (int, long)), id
+        assert isinstance(id, six.integer_types), id
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/keys/" + str(id)
@@ -2149,10 +2151,10 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param name: string
         :rtype: :class:`github.Label.Label`
         """
-        assert isinstance(name, (str, unicode)), name
+        assert isinstance(name, (str, six.text_type)), name
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
-            self.url + "/labels/" + urllib.quote(name)
+            self.url + "/labels/" + six.moves.urllib.parse.quote(name)
         )
         return github.Label.Label(self._requester, headers, data, completed=True)
 
@@ -2197,7 +2199,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param number: integer
         :rtype: :class:`github.Milestone.Milestone`
         """
-        assert isinstance(number, (int, long)), number
+        assert isinstance(number, six.integer_types), number
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/milestones/" + str(number)
@@ -2212,9 +2214,9 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param direction: string
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Milestone.Milestone`
         """
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         url_parameters = dict()
         if state is not github.GithubObject.NotSet:
             url_parameters["state"] = state
@@ -2247,7 +2249,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param number: integer
         :rtype: :class:`github.PullRequest.PullRequest`
         """
-        assert isinstance(number, (int, long)), number
+        assert isinstance(number, six.integer_types), number
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
             self.url + "/pulls/" + str(number)
@@ -2264,11 +2266,11 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param head: string
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.PullRequest.PullRequest`
         """
-        assert state is github.GithubObject.NotSet or isinstance(state, (str, unicode)), state
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
-        assert base is github.GithubObject.NotSet or isinstance(base, (str, unicode)), base
-        assert head is github.GithubObject.NotSet or isinstance(head, (str, unicode)), head
+        assert state is github.GithubObject.NotSet or isinstance(state, (str, six.text_type)), state
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
+        assert base is github.GithubObject.NotSet or isinstance(base, (str, six.text_type)), base
+        assert head is github.GithubObject.NotSet or isinstance(head, (str, six.text_type)), head
         url_parameters = dict()
         if state is not github.GithubObject.NotSet:
             url_parameters["state"] = state
@@ -2305,8 +2307,8 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param since: datetime.datetime
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.PullRequestComment.PullRequestComment`
         """
-        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
-        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
+        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, six.text_type)), sort
+        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, six.text_type)), direction
         assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
         url_parameters = dict()
         if sort is not github.GithubObject.NotSet:
@@ -2328,7 +2330,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param ref: string
         :rtype: :class:`github.ContentFile.ContentFile`
         """
-        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, unicode)), ref
+        assert ref is github.GithubObject.NotSet or isinstance(ref, (str, six.text_type)), ref
         url_parameters = dict()
         if ref is not github.GithubObject.NotSet:
             url_parameters["ref"] = ref
@@ -2507,7 +2509,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
                 self.url + "/releases/" + str(id)
             )
             return github.GitRelease.GitRelease(self._requester, headers, data, completed=True)
-        elif isinstance(id, (str, unicode)):
+        elif isinstance(id, (str, six.text_type)):
             headers, data = self._requester.requestJsonAndCheck(
                 "GET",
                 self.url + "/releases/tags/" + id
@@ -2567,7 +2569,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param assignee: string or :class:`github.NamedUser.NamedUser`
         :rtype: bool
         """
-        assert isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, unicode)), assignee
+        assert isinstance(assignee, github.NamedUser.NamedUser) or isinstance(assignee, (str, six.text_type)), assignee
 
         if isinstance(assignee, github.NamedUser.NamedUser):
             assignee = assignee._identity
@@ -2584,7 +2586,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param collaborator: string or :class:`github.NamedUser.NamedUser`
         :rtype: bool
         """
-        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, unicode)), collaborator
+        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, six.text_type)), collaborator
 
         if isinstance(collaborator, github.NamedUser.NamedUser):
             collaborator = collaborator._identity
@@ -2603,10 +2605,10 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Issue.Issue`
         """
         assert state in ["open", "closed"], state
-        assert isinstance(keyword, (str, unicode)), keyword
+        assert isinstance(keyword, (str, six.text_type)), keyword
         headers, data = self._requester.requestJsonAndCheck(
             "GET",
-            "/legacy/issues/search/" + self.owner.login + "/" + self.name + "/" + state + "/" + urllib.quote(keyword)
+            "/legacy/issues/search/" + self.owner.login + "/" + self.name + "/" + state + "/" + six.moves.urllib.parse.quote(keyword)
         )
         return [
             github.Issue.Issue(self._requester, headers, github.Legacy.convertIssue(element), completed=False)
@@ -2637,9 +2639,9 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param commit_message: string
         :rtype: :class:`github.Commit.Commit`
         """
-        assert isinstance(base, (str, unicode)), base
-        assert isinstance(head, (str, unicode)), head
-        assert commit_message is github.GithubObject.NotSet or isinstance(commit_message, (str, unicode)), commit_message
+        assert isinstance(base, (str, six.text_type)), base
+        assert isinstance(head, (str, six.text_type)), head
+        assert commit_message is github.GithubObject.NotSet or isinstance(commit_message, (str, six.text_type)), commit_message
         post_parameters = {
             "base": base,
             "head": head,
@@ -2678,7 +2680,7 @@ class Repository(github.GithubObject.CompletableGithubObject):
         :param collaborator: string or :class:`github.NamedUser.NamedUser`
         :rtype: None
         """
-        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, unicode)), collaborator
+        assert isinstance(collaborator, github.NamedUser.NamedUser) or isinstance(collaborator, (str, six.text_type)), collaborator
 
         if isinstance(collaborator, github.NamedUser.NamedUser):
             collaborator = collaborator._identity
@@ -2709,10 +2711,10 @@ class Repository(github.GithubObject.CompletableGithubObject):
         return self._hub("unsubscribe", event, callback, github.GithubObject.NotSet)
 
     def _hub(self, mode, event, callback, secret):
-        assert isinstance(mode, (str, unicode)), mode
-        assert isinstance(event, (str, unicode)), event
-        assert isinstance(callback, (str, unicode)), callback
-        assert secret is github.GithubObject.NotSet or isinstance(secret, (str, unicode)), secret
+        assert isinstance(mode, (str, six.text_type)), mode
+        assert isinstance(event, (str, six.text_type)), event
+        assert isinstance(callback, (str, six.text_type)), callback
+        assert secret is github.GithubObject.NotSet or isinstance(secret, (str, six.text_type)), secret
 
         post_parameters = {
             "hub.mode": mode,
diff --git a/github/RepositoryKey.py b/github/RepositoryKey.py
index e3c29758..a1de7d61 100644
--- a/github/RepositoryKey.py
+++ b/github/RepositoryKey.py
@@ -35,6 +35,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Requester.py b/github/Requester.py
index 6eb51e8d..63daaac2 100644
--- a/github/Requester.py
+++ b/github/Requester.py
@@ -52,6 +52,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import base64
 import json
 import logging
@@ -61,12 +62,13 @@ import re
 import requests
 import sys
 import time
-import urllib
-import urlparse
+import six.moves.urllib.request, six.moves.urllib.parse, six.moves.urllib.error
+import six.moves.urllib.parse
 from io import IOBase
 
-import Consts
-import GithubException
+from . import Consts
+from . import GithubException
+import six
 
 atLeastPython3 = sys.hexversion >= 0x03000000
 
@@ -80,9 +82,9 @@ class RequestsResponse:
 
     def getheaders(self):
         if atLeastPython3:
-            return self.headers.items()
+            return list(self.headers.items())
         else:
-            return self.headers.iteritems()
+            return six.iteritems(self.headers)
 
     def read(self):
         return self.text
@@ -243,7 +245,7 @@ class Requester:
             self.__authorizationHeader = None
 
         self.__base_url = base_url
-        o = urlparse.urlparse(base_url)
+        o = six.moves.urllib.parse.urlparse(base_url)
         self.__hostname = o.hostname
         self.__port = o.port
         self.__prefix = o.path
@@ -290,7 +292,7 @@ class Requester:
     def __customConnection(self, url):
         cnx = None
         if not url.startswith("/"):
-            o = urlparse.urlparse(url)
+            o = six.moves.urllib.parse.urlparse(url)
             if o.hostname != self.__hostname or \
                (o.port and o.port != self.__port) or \
                (o.scheme != self.__scheme and not (o.scheme == "https" and self.__scheme == "http")):  # issue80
@@ -341,7 +343,7 @@ class Requester:
             eol = "\r\n"
 
             encoded_input = ""
-            for name, value in input.iteritems():
+            for name, value in six.iteritems(input):
                 encoded_input += "--" + boundary + eol
                 encoded_input += "Content-Disposition: form-data; name=\"" + name + "\"" + eol
                 encoded_input += eol
@@ -428,7 +430,7 @@ class Requester:
             return self.__requestRaw(original_cnx, verb, url, requestHeaders, input)
 
         if status == 301 and 'location' in responseHeaders:
-            o = urlparse.urlparse(responseHeaders['location'])
+            o = six.moves.urllib.parse.urlparse(responseHeaders['location'])
             return self.__requestRaw(original_cnx, verb, o.path, requestHeaders, input)
 
         return status, responseHeaders, output
@@ -446,7 +448,7 @@ class Requester:
         if url.startswith("/"):
             url = self.__prefix + url
         else:
-            o = urlparse.urlparse(url)
+            o = six.moves.urllib.parse.urlparse(url)
             assert o.hostname in [self.__hostname, "uploads.github.com", "status.github.com"], o.hostname
             assert o.path.startswith((self.__prefix, "/api/"))
             assert o.port == self.__port
@@ -459,7 +461,7 @@ class Requester:
         if len(parameters) == 0:
             return url
         else:
-            return url + "?" + urllib.urlencode(parameters)
+            return url + "?" + six.moves.urllib.parse.urlencode(parameters)
 
     def __createConnection(self):
         kwds = {}
diff --git a/github/RequiredPullRequestReviews.py b/github/RequiredPullRequestReviews.py
index c3da7be4..0ffbfa54 100644
--- a/github/RequiredPullRequestReviews.py
+++ b/github/RequiredPullRequestReviews.py
@@ -22,6 +22,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
diff --git a/github/RequiredStatusChecks.py b/github/RequiredStatusChecks.py
index e4fba2e1..24be0c0f 100644
--- a/github/RequiredStatusChecks.py
+++ b/github/RequiredStatusChecks.py
@@ -22,6 +22,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/SourceImport.py b/github/SourceImport.py
index 26a60d2c..2e9671d5 100644
--- a/github/SourceImport.py
+++ b/github/SourceImport.py
@@ -22,6 +22,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/Stargazer.py b/github/Stargazer.py
index 335bd840..add2423f 100644
--- a/github/Stargazer.py
+++ b/github/Stargazer.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github
 
 
diff --git a/github/StatsCodeFrequency.py b/github/StatsCodeFrequency.py
index aab58812..5f6b42aa 100755
--- a/github/StatsCodeFrequency.py
+++ b/github/StatsCodeFrequency.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/StatsCommitActivity.py b/github/StatsCommitActivity.py
index ade32342..a8e39714 100755
--- a/github/StatsCommitActivity.py
+++ b/github/StatsCommitActivity.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/StatsContributor.py b/github/StatsContributor.py
index 7b8d0db7..f21980b8 100755
--- a/github/StatsContributor.py
+++ b/github/StatsContributor.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
diff --git a/github/StatsParticipation.py b/github/StatsParticipation.py
index 326496f5..b51d4a44 100755
--- a/github/StatsParticipation.py
+++ b/github/StatsParticipation.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
diff --git a/github/StatsPunchCard.py b/github/StatsPunchCard.py
index 01a472c8..925b2f03 100755
--- a/github/StatsPunchCard.py
+++ b/github/StatsPunchCard.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.NamedUser
diff --git a/github/Tag.py b/github/Tag.py
index 17033042..0315dc24 100644
--- a/github/Tag.py
+++ b/github/Tag.py
@@ -31,6 +31,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 import github.Commit
diff --git a/github/Team.py b/github/Team.py
index a5d56a66..a6df41a6 100644
--- a/github/Team.py
+++ b/github/Team.py
@@ -41,6 +41,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 import github.PaginatedList
 
@@ -48,7 +49,8 @@ import github.Repository
 import github.NamedUser
 import github.Organization
 
-import Consts
+from . import Consts
+import six
 
 
 class Team(github.GithubObject.CompletableGithubObject):
@@ -179,7 +181,7 @@ class Team(github.GithubObject.CompletableGithubObject):
         """
         assert isinstance(member, github.NamedUser.NamedUser), member
         assert role is github.GithubObject.NotSet or isinstance(
-            role, (str, unicode)), role
+            role, (str, six.text_type)), role
         if role is not github.GithubObject.NotSet:
             assert role in ['member', 'maintainer']
             put_parameters = {
@@ -243,10 +245,10 @@ class Team(github.GithubObject.CompletableGithubObject):
         :param privacy: string
         :rtype: None
         """
-        assert isinstance(name, (str, unicode)), name
-        assert description is github.GithubObject.NotSet or isinstance(description, (str, unicode)), description
-        assert permission is github.GithubObject.NotSet or isinstance(permission, (str, unicode)), permission
-        assert privacy is github.GithubObject.NotSet or isinstance(privacy, (str, unicode)), privacy
+        assert isinstance(name, (str, six.text_type)), name
+        assert description is github.GithubObject.NotSet or isinstance(description, (str, six.text_type)), description
+        assert permission is github.GithubObject.NotSet or isinstance(permission, (str, six.text_type)), permission
+        assert privacy is github.GithubObject.NotSet or isinstance(privacy, (str, six.text_type)), privacy
         post_parameters = {
             "name": name,
         }
@@ -269,7 +271,7 @@ class Team(github.GithubObject.CompletableGithubObject):
         :param role: string
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
         """
-        assert role is github.GithubObject.NotSet or isinstance(role, (str, unicode)), role
+        assert role is github.GithubObject.NotSet or isinstance(role, (str, six.text_type)), role
         url_parameters = dict()
         if role is not github.GithubObject.NotSet:
             assert role in ['member', 'maintainer', 'all']
diff --git a/github/Topic.py b/github/Topic.py
index c347c2c2..99fed6e9 100644
--- a/github/Topic.py
+++ b/github/Topic.py
@@ -22,6 +22,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/UserKey.py b/github/UserKey.py
index a01a867f..9f9ac594 100644
--- a/github/UserKey.py
+++ b/github/UserKey.py
@@ -31,6 +31,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/View.py b/github/View.py
index ed0bce5d..f64078dd 100644
--- a/github/View.py
+++ b/github/View.py
@@ -26,6 +26,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github.GithubObject
 
 
diff --git a/github/__init__.py b/github/__init__.py
index 8475e734..ff539ff1 100644
--- a/github/__init__.py
+++ b/github/__init__.py
@@ -37,13 +37,14 @@ like :class:`github.NamedUser.NamedUser` or :class:`github.Repository.Repository
 All classes inherit from :class:`github.GithubObject.GithubObject`.
 """
 
+from __future__ import absolute_import
 import logging
 
 from github.MainClass import Github, GithubIntegration
-from GithubException import GithubException, BadCredentialsException, UnknownObjectException, BadUserAgentException, RateLimitExceededException, BadAttributeException, TwoFactorException
-from InputFileContent import InputFileContent
-from InputGitAuthor import InputGitAuthor
-from InputGitTreeElement import InputGitTreeElement
+from .GithubException import GithubException, BadCredentialsException, UnknownObjectException, BadUserAgentException, RateLimitExceededException, BadAttributeException, TwoFactorException
+from .InputFileContent import InputFileContent
+from .InputGitAuthor import InputGitAuthor
+from .InputGitTreeElement import InputGitTreeElement
 
 
 def enable_console_debug_logging():  # pragma no cover (Function useful only outside test environment)
diff --git a/requirements.txt b/requirements.txt
index d678b9ff..e29381df 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,6 @@
 requests>=2.14.0
 pyjwt
+six
 sphinx<1.8
 sphinx-rtd-theme<0.5
 Deprecated
diff --git a/scripts/add_attribute.py b/scripts/add_attribute.py
index 52332b4c..6c3945e2 100644
--- a/scripts/add_attribute.py
+++ b/scripts/add_attribute.py
@@ -28,6 +28,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import sys
 import os.path
 
diff --git a/scripts/fix_headers.py b/scripts/fix_headers.py
index 7b7813bb..bb764102 100755
--- a/scripts/fix_headers.py
+++ b/scripts/fix_headers.py
@@ -26,6 +26,8 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
+from __future__ import print_function
 import os
 import subprocess
 
@@ -153,17 +155,17 @@ def findHeadersAndFiles():
             elif fullname.endswith(".pyc"):
                 pass
             else:
-                print "Don't know what to do with", filename
+                print("Don't know what to do with", filename)
 
 
 def main():
     for header, filename in findHeadersAndFiles():
-        print "Analyzing", filename
+        print("Analyzing", filename)
         with open(filename) as f:
             lines = list(line.rstrip() for line in f)
         newLines = header.fix(filename, lines)
         if newLines != lines:
-            print " => actually modifying", filename
+            print(" => actually modifying", filename)
             with open(filename, "w") as f:
                 for line in newLines:
                     f.write(line + "\n")
diff --git a/tests/AllTests.py b/tests/AllTests.py
index 98bbb2e5..84b172e2 100644
--- a/tests/AllTests.py
+++ b/tests/AllTests.py
@@ -40,90 +40,91 @@
 #                                                                              #
 ################################################################################
 
-from AuthenticatedUser import *
-from Authentication import *
-from Authorization import *
-from Branch import *
-from BranchProtection import *
-from Commit import *
-from CommitCombinedStatus import *
-from CommitComment import *
-from CommitStatus import *
-from ContentFile import *
-from Download import *
-from Event import *
-from Gist import *
-from GistComment import *
-from GitBlob import *
-from GitCommit import *
-from Github_ import *
-from GitRef import *
-from GitRelease import *
-from GitReleaseAsset import *
-from GitTag import *
-from GitTree import *
-from Hook import *
-from Issue import *
-from IssueComment import *
-from Reaction import *
-from IssueEvent import *
-from License import *
-from Label import *
-from Milestone import *
-from NamedUser import *
-from Markdown import *
-from Notification import *
-from OrganizationHasInMembers import *
-from Organization import *
-from Project import *
-from PullRequest import *
-from PullRequestComment import *
-from PullRequestReview import *
-from PullRequestFile import *
-from RateLimiting import *
-from Repository import *
-from RepositoryKey import *
-from RequiredPullRequestReviews import *
-from RequiredStatusChecks import *
-from SourceImport import *
-from Tag import *
-from Team import *
-from Traffic import *
-from UserKey import *
-from Migration import *
-from GithubIntegration import *
+from __future__ import absolute_import
+from .AuthenticatedUser import *
+from .Authentication import *
+from .Authorization import *
+from .Branch import *
+from .BranchProtection import *
+from .Commit import *
+from .CommitCombinedStatus import *
+from .CommitComment import *
+from .CommitStatus import *
+from .ContentFile import *
+from .Download import *
+from .Event import *
+from .Gist import *
+from .GistComment import *
+from .GitBlob import *
+from .GitCommit import *
+from .Github_ import *
+from .GitRef import *
+from .GitRelease import *
+from .GitReleaseAsset import *
+from .GitTag import *
+from .GitTree import *
+from .Hook import *
+from .Issue import *
+from .IssueComment import *
+from .Reaction import *
+from .IssueEvent import *
+from .License import *
+from .Label import *
+from .Milestone import *
+from .NamedUser import *
+from .Markdown import *
+from .Notification import *
+from .OrganizationHasInMembers import *
+from .Organization import *
+from .Project import *
+from .PullRequest import *
+from .PullRequestComment import *
+from .PullRequestReview import *
+from .PullRequestFile import *
+from .RateLimiting import *
+from .Repository import *
+from .RepositoryKey import *
+from .RequiredPullRequestReviews import *
+from .RequiredStatusChecks import *
+from .SourceImport import *
+from .Tag import *
+from .Team import *
+from .Traffic import *
+from .UserKey import *
+from .Migration import *
+from .GithubIntegration import *
 
-from PaginatedList import *
-from Exceptions import *
-from Enterprise import *
-from Logging_ import *
-from RawData import *
-from ConditionalRequestUpdate import *
-from Persistence import *
-from ExposeAllAttributes import *
-from BadAttributes import *
-from Equality import *
-from Search import *
-from Retry import *
+from .PaginatedList import *
+from .Exceptions import *
+from .Enterprise import *
+from .Logging_ import *
+from .RawData import *
+from .ConditionalRequestUpdate import *
+from .Persistence import *
+from .ExposeAllAttributes import *
+from .BadAttributes import *
+from .Equality import *
+from .Search import *
+from .Retry import *
 
-from Issue33 import *
-from Issue50 import *
-from Issue54 import *
-from Issue80 import *
-from Issue87 import *
-from Issue131 import *
-from Issue133 import *
-from Issue134 import *
-from Issue139 import *
-from Issue140 import *
-from Issue142 import *
-from Issue158 import *
-from Issue174 import *
-from Issue214 import *
-from Issue216 import *
-from Issue278 import *
-from Issue494 import *
-from Issue572 import *
-from Issue937 import *
-from Issue945 import *
-from Issue823 import *
\ No newline at end of file
+from .Issue33 import *
+from .Issue50 import *
+from .Issue54 import *
+from .Issue80 import *
+from .Issue87 import *
+from .Issue131 import *
+from .Issue133 import *
+from .Issue134 import *
+from .Issue139 import *
+from .Issue140 import *
+from .Issue142 import *
+from .Issue158 import *
+from .Issue174 import *
+from .Issue214 import *
+from .Issue216 import *
+from .Issue278 import *
+from .Issue494 import *
+from .Issue572 import *
+from .Issue937 import *
+from .Issue945 import *
+from .Issue823 import *
\ No newline at end of file
diff --git a/tests/AuthenticatedUser.py b/tests/AuthenticatedUser.py
index 9da32ad9..2b2de785 100644
--- a/tests/AuthenticatedUser.py
+++ b/tests/AuthenticatedUser.py
@@ -32,7 +32,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import github
 import datetime
@@ -167,13 +168,13 @@ class AuthenticatedUser(Framework.TestCase):
     def testCreateGist(self):
         gist = self.user.create_gist(True, {"foobar.txt": github.InputFileContent("File created by PyGithub")}, "Gist created by PyGithub")
         self.assertEqual(gist.description, "Gist created by PyGithub")
-        self.assertEqual(gist.files.keys(), ["foobar.txt"])
+        self.assertEqual(list(gist.files.keys()), ["foobar.txt"])
         self.assertEqual(gist.files["foobar.txt"].content, "File created by PyGithub")
 
     def testCreateGistWithoutDescription(self):
         gist = self.user.create_gist(True, {"foobar.txt": github.InputFileContent("File created by PyGithub")})
         self.assertEqual(gist.description, None)
-        self.assertEqual(gist.files.keys(), ["foobar.txt"])
+        self.assertEqual(list(gist.files.keys()), ["foobar.txt"])
         self.assertEqual(gist.files["foobar.txt"].content, "File created by PyGithub")
 
     def testCreateKey(self):
@@ -245,7 +246,7 @@ class AuthenticatedUser(Framework.TestCase):
         self.assertListKeyEqual(self.user.get_notifications(all=True), lambda n: n.id, [])
 
     def testMarkNotificationsAsRead(self):
-        self.user.mark_notifications_as_read(datetime.datetime(2018, 10, 18, 18, 20, 01, 0))
+        self.user.mark_notifications_as_read(datetime.datetime(2018, 10, 18, 18, 20, 0o1, 0))
 
     def testGetTeams(self):
         self.assertListKeyEqual(self.user.get_teams(), lambda t: t.name, ["Owners", "Honoraries", "Honoraries", "Honoraries", "Honoraries", "Honoraries", "Honoraries", "Honoraries", "Honoraries", "Honoraries"])
diff --git a/tests/Authentication.py b/tests/Authentication.py
index 1edf7881..2c1213d9 100644
--- a/tests/Authentication.py
+++ b/tests/Authentication.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 import github
 
 
diff --git a/tests/Authorization.py b/tests/Authorization.py
index 14be38ed..78350b60 100644
--- a/tests/Authorization.py
+++ b/tests/Authorization.py
@@ -27,7 +27,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/BadAttributes.py b/tests/BadAttributes.py
index d8f19971..69bb1b76 100755
--- a/tests/BadAttributes.py
+++ b/tests/BadAttributes.py
@@ -26,10 +26,12 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
-import Framework
+from . import Framework
 import github
+import six
 
 
 # Replay data is forged to simulate bad things returned by Github
@@ -41,7 +43,7 @@ class BadAttributes(Framework.TestCase):
         with self.assertRaises(github.BadAttributeException) as raisedexp:
             user.name
         self.assertEqual(raisedexp.exception.actual_value, 42)
-        self.assertEqual(raisedexp.exception.expected_type, (str, unicode))
+        self.assertEqual(raisedexp.exception.expected_type, (str, six.text_type))
         self.assertEqual(raisedexp.exception.transformation_exception, None)
 
     def testBadAttributeTransformation(self):
@@ -51,7 +53,7 @@ class BadAttributes(Framework.TestCase):
         with self.assertRaises(github.BadAttributeException) as raisedexp:
             user.created_at
         self.assertEqual(raisedexp.exception.actual_value, "foobar")
-        self.assertEqual(raisedexp.exception.expected_type, (str, unicode))
+        self.assertEqual(raisedexp.exception.expected_type, (str, six.text_type))
         self.assertEqual(raisedexp.exception.transformation_exception.__class__, ValueError)
         self.assertEqual(raisedexp.exception.transformation_exception.args, ("time data 'foobar' does not match format '%Y-%m-%dT%H:%M:%SZ'",))
 
@@ -62,7 +64,7 @@ class BadAttributes(Framework.TestCase):
         with self.assertRaises(github.BadAttributeException) as raisedexp:
             user.updated_at
         self.assertEqual(raisedexp.exception.actual_value, 42)
-        self.assertEqual(raisedexp.exception.expected_type, (str, unicode))
+        self.assertEqual(raisedexp.exception.expected_type, (str, six.text_type))
         self.assertEqual(raisedexp.exception.transformation_exception, None)
 
     def testBadSimpleAttributeInList(self):
@@ -72,7 +74,7 @@ class BadAttributes(Framework.TestCase):
         with self.assertRaises(github.BadAttributeException) as raisedexp:
             hook.events
         self.assertEqual(raisedexp.exception.actual_value, ["push", 42])
-        self.assertEqual(raisedexp.exception.expected_type, [(str, unicode)])
+        self.assertEqual(raisedexp.exception.expected_type, [(str, six.text_type)])
         self.assertEqual(raisedexp.exception.transformation_exception, None)
 
     def testBadAttributeInClassAttribute(self):
@@ -99,7 +101,7 @@ class BadAttributes(Framework.TestCase):
         with self.assertRaises(github.BadAttributeException) as raisedexp:
             gist.files
         self.assertEqual(raisedexp.exception.actual_value, {"test.py": 42})
-        self.assertEqual(raisedexp.exception.expected_type, {(str, unicode): dict})
+        self.assertEqual(raisedexp.exception.expected_type, {(str, six.text_type): dict})
         self.assertEqual(raisedexp.exception.transformation_exception, None)
 
     def testIssue195(self):
@@ -115,5 +117,5 @@ class BadAttributes(Framework.TestCase):
                 with self.assertRaises(github.BadAttributeException) as raisedexp:
                     hook.events
         self.assertEqual(raisedexp.exception.actual_value, [["commit_comment", "create", "delete", "download", "follow", "fork", "fork_apply", "gist", "gollum", "issue_comment", "issues", "member", "public", "pull_request", "pull_request_review_comment", "push", "status", "team_add", "watch"]])
-        self.assertEqual(raisedexp.exception.expected_type, [(str, unicode)])
+        self.assertEqual(raisedexp.exception.expected_type, [(str, six.text_type)])
         self.assertEqual(raisedexp.exception.transformation_exception, None)
diff --git a/tests/Branch.py b/tests/Branch.py
index 0764a043..f86a689a 100644
--- a/tests/Branch.py
+++ b/tests/Branch.py
@@ -30,7 +30,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import github
 
diff --git a/tests/BranchProtection.py b/tests/BranchProtection.py
index 19a655d4..d5f19351 100644
--- a/tests/BranchProtection.py
+++ b/tests/BranchProtection.py
@@ -22,7 +22,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class BranchProtection(Framework.TestCase):
diff --git a/tests/Commit.py b/tests/Commit.py
index 82e5e971..ea863046 100644
--- a/tests/Commit.py
+++ b/tests/Commit.py
@@ -29,7 +29,9 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
+import six
 
 
 class Commit(Framework.TestCase):
@@ -48,7 +50,7 @@ class Commit(Framework.TestCase):
         self.assertEqual(self.commit.files[0].changes, 20)
         self.assertEqual(self.commit.files[0].deletions, 20)
         self.assertEqual(self.commit.files[0].filename, "github/GithubObjects/GitAuthor.py")
-        self.assertTrue(isinstance(self.commit.files[0].patch, (str, unicode)))
+        self.assertTrue(isinstance(self.commit.files[0].patch, (str, six.text_type)))
         self.assertEqual(self.commit.files[0].raw_url, "https://github.com/jacquev6/PyGithub/raw/1292bf0e22c796e91cc3d6e24b544aece8c21f2a/github/GithubObjects/GitAuthor.py")
         self.assertEqual(self.commit.files[0].sha, "1292bf0e22c796e91cc3d6e24b544aece8c21f2a")
         self.assertEqual(self.commit.files[0].status, "modified")
diff --git a/tests/CommitCombinedStatus.py b/tests/CommitCombinedStatus.py
index 1ed79167..e3adbd46 100644
--- a/tests/CommitCombinedStatus.py
+++ b/tests/CommitCombinedStatus.py
@@ -26,7 +26,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/CommitComment.py b/tests/CommitComment.py
index 48106326..5cbb3cbc 100644
--- a/tests/CommitComment.py
+++ b/tests/CommitComment.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/CommitStatus.py b/tests/CommitStatus.py
index 60baad67..50be17ae 100644
--- a/tests/CommitStatus.py
+++ b/tests/CommitStatus.py
@@ -30,7 +30,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/ConditionalRequestUpdate.py b/tests/ConditionalRequestUpdate.py
index 01ea2cf2..799a30ce 100644
--- a/tests/ConditionalRequestUpdate.py
+++ b/tests/ConditionalRequestUpdate.py
@@ -27,7 +27,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class ConditionalRequestUpdate(Framework.TestCase):
diff --git a/tests/ContentFile.py b/tests/ContentFile.py
index 18b02805..a5d903d8 100644
--- a/tests/ContentFile.py
+++ b/tests/ContentFile.py
@@ -30,7 +30,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class ContentFile(Framework.TestCase):
diff --git a/tests/Download.py b/tests/Download.py
index 9b224276..11072f10 100644
--- a/tests/Download.py
+++ b/tests/Download.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/Enterprise.py b/tests/Enterprise.py
index 5e538429..81e441fe 100644
--- a/tests/Enterprise.py
+++ b/tests/Enterprise.py
@@ -27,9 +27,10 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github
 
-import Framework
+from . import Framework
 
 
 # Replay data for this test case is forged, because I don't have access to a real Github Enterprise install
diff --git a/tests/Equality.py b/tests/Equality.py
index b4e6347e..9b11d6df 100755
--- a/tests/Equality.py
+++ b/tests/Equality.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Equality(Framework.TestCase):
diff --git a/tests/Event.py b/tests/Event.py
index 8b37bc1b..5cb4ec6a 100644
--- a/tests/Event.py
+++ b/tests/Event.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/Exceptions.py b/tests/Exceptions.py
index e3902550..07fe936a 100644
--- a/tests/Exceptions.py
+++ b/tests/Exceptions.py
@@ -31,11 +31,13 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github
 import sys
 import pickle
 
-import Framework
+from . import Framework
+from six.moves import range
 
 atMostPython2 = sys.hexversion < 0x03000000
 
diff --git a/tests/ExposeAllAttributes.py b/tests/ExposeAllAttributes.py
index 9e93c572..22161deb 100644
--- a/tests/ExposeAllAttributes.py
+++ b/tests/ExposeAllAttributes.py
@@ -25,7 +25,10 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from __future__ import print_function
+from . import Framework
+import six
 
 
 class ExposeAllAttributes(Framework.TestCase):
@@ -128,9 +131,9 @@ class ExposeAllAttributes(Framework.TestCase):
             # userKey,  # Security issue if put as-is in ReplayData
         ])
 
-        for className, attributesMissingInClass in sorted(missingAttributes.iteritems()):
-            for attrName, value in sorted(attributesMissingInClass.iteritems()):
-                print className, attrName, "->", repr(value)
+        for className, attributesMissingInClass in sorted(six.iteritems(missingAttributes)):
+            for attrName, value in sorted(six.iteritems(attributesMissingInClass)):
+                print(className, attrName, "->", repr(value))
 
         self.assertEqual(sum(len(attrs) for attrs in missingAttributes.values()), 0)
 
diff --git a/tests/Framework.py b/tests/Framework.py
index a3553305..8e19f267 100644
--- a/tests/Framework.py
+++ b/tests/Framework.py
@@ -36,6 +36,8 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
+from __future__ import print_function
 import json
 import os
 import sys
@@ -46,6 +48,7 @@ from requests.structures import CaseInsensitiveDict
 from urllib3.util import Url
 
 import github
+import six
 
 python2 = sys.hexversion < 0x03000000
 atLeastPython3 = sys.hexversion >= 0x03000000
@@ -96,7 +99,7 @@ class RecordingConnection:  # pragma no cover (Class useful only when recording
         self.__cnx = self._realConnection(host, port, *args, **kwds)
 
     def request(self, verb, url, input, headers):
-        print verb, url, input, headers,
+        print(verb, url, input, headers, end=' ')
         self.__cnx.request(verb, url, input, headers)
         # fixAuthorizationHeader changes the parameter directly to remove Authorization token.
         # however, this is the real dictionary that *will be sent* by "requests",
@@ -119,7 +122,7 @@ class RecordingConnection:  # pragma no cover (Class useful only when recording
         res = self.__cnx.getresponse()
 
         status = res.status
-        print "=>", status
+        print("=>", status)
         headers = res.getheaders()
         output = res.read()
 
@@ -191,7 +194,7 @@ class ReplayingConnection:
         self.__testCase.assertEqual(self.__splitUrl(url), self.__splitUrl(readLine(self.__file)))
         self.__testCase.assertEqual(headers, eval(readLine(self.__file)))
         expectedInput = readLine(self.__file)
-        if isinstance(input, (str, unicode)):
+        if isinstance(input, (str, six.text_type)):
             if input.startswith("{"):
                 self.__testCase.assertEqual(json.loads(input.replace('\n', '').replace('\r', '')), json.loads(expectedInput))
             elif python2:  # @todo Test in all cases, including Python 3.4+
diff --git a/tests/Gist.py b/tests/Gist.py
index 1849f5ad..0685b545 100644
--- a/tests/Gist.py
+++ b/tests/Gist.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import github
 import datetime
@@ -40,7 +41,7 @@ class Gist(Framework.TestCase):
         self.assertEqual(gist.comments, 0)
         self.assertEqual(gist.created_at, datetime.datetime(2013, 8, 21, 16, 28, 24))
         self.assertEqual(gist.description, "Github API")
-        self.assertEqual(gist.files.keys(), ["GithubAPI.lua"])
+        self.assertEqual(list(gist.files.keys()), ["GithubAPI.lua"])
         self.assertEqual(gist.files["GithubAPI.lua"].size, 21229)
         self.assertEqual(gist.files["GithubAPI.lua"].filename, "GithubAPI.lua")
         self.assertEqual(gist.files["GithubAPI.lua"].language, "Lua")
@@ -90,13 +91,13 @@ class Gist(Framework.TestCase):
         gist = self.g.get_gist("5339374")
         self.assertEqual(sorted(gist.files.keys()), ["bar.txt", "foo.txt"])
         gist.edit(files={"foo.txt": None})
-        self.assertEqual(gist.files.keys(), ["bar.txt"])
+        self.assertEqual(list(gist.files.keys()), ["bar.txt"])
 
     def testRenameFile(self):
         gist = self.g.get_gist("5339374")
-        self.assertEqual(gist.files.keys(), ["bar.txt"])
+        self.assertEqual(list(gist.files.keys()), ["bar.txt"])
         gist.edit(files={"bar.txt": github.InputFileContent(gist.files["bar.txt"].content, new_name="baz.txt")})
-        self.assertEqual(gist.files.keys(), ["baz.txt"])
+        self.assertEqual(list(gist.files.keys()), ["baz.txt"])
 
     def testCreateComment(self):
         gist = self.g.get_gist("2729810")
diff --git a/tests/GistComment.py b/tests/GistComment.py
index 5d751e11..2d57dc38 100644
--- a/tests/GistComment.py
+++ b/tests/GistComment.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/GitBlob.py b/tests/GitBlob.py
index 06369b60..69caa9b3 100644
--- a/tests/GitBlob.py
+++ b/tests/GitBlob.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class GitBlob(Framework.TestCase):
diff --git a/tests/GitCommit.py b/tests/GitCommit.py
index 4ed79e68..db7d5123 100644
--- a/tests/GitCommit.py
+++ b/tests/GitCommit.py
@@ -29,9 +29,10 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
-import Framework
+from . import Framework
 
 
 class GitCommit(Framework.TestCase):
diff --git a/tests/GitRef.py b/tests/GitRef.py
index 44b43cc5..84590727 100644
--- a/tests/GitRef.py
+++ b/tests/GitRef.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class GitRef(Framework.TestCase):
diff --git a/tests/GitRelease.py b/tests/GitRelease.py
index bb861c64..c1cb4f03 100644
--- a/tests/GitRelease.py
+++ b/tests/GitRelease.py
@@ -34,10 +34,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import os
 import zipfile
 import datetime
-import Framework
+from . import Framework
 
 
 class Release(Framework.TestCase):
diff --git a/tests/GitReleaseAsset.py b/tests/GitReleaseAsset.py
index 0ba71ee5..9a76aede 100644
--- a/tests/GitReleaseAsset.py
+++ b/tests/GitReleaseAsset.py
@@ -24,8 +24,9 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
-import Framework
+from . import Framework
 
 
 class ReleaseAsset(Framework.TestCase):
diff --git a/tests/GitTag.py b/tests/GitTag.py
index 2246a08e..a22133ab 100644
--- a/tests/GitTag.py
+++ b/tests/GitTag.py
@@ -29,9 +29,10 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
-import Framework
+from . import Framework
 
 
 class GitTag(Framework.TestCase):
diff --git a/tests/GitTree.py b/tests/GitTree.py
index 7f12066b..cd38b7f5 100644
--- a/tests/GitTree.py
+++ b/tests/GitTree.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class GitTree(Framework.TestCase):
diff --git a/tests/GithubIntegration.py b/tests/GithubIntegration.py
index 28f13fdc..e8c1f85a 100644
--- a/tests/GithubIntegration.py
+++ b/tests/GithubIntegration.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import jwt
 import json
 import time # NOQA
diff --git a/tests/Github_.py b/tests/Github_.py
index 484a3424..5bf97f2f 100644
--- a/tests/Github_.py
+++ b/tests/Github_.py
@@ -32,11 +32,12 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
-import Framework
+from . import Framework
 
-import Time
+from . import Time
 
 import github
 
diff --git a/tests/Hook.py b/tests/Hook.py
index cd48f543..8631f2e0 100644
--- a/tests/Hook.py
+++ b/tests/Hook.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/Issue.py b/tests/Issue.py
index 54097ae1..d212607d 100644
--- a/tests/Issue.py
+++ b/tests/Issue.py
@@ -32,7 +32,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/Issue131.py b/tests/Issue131.py
index fef68929..76dac6ec 100644
--- a/tests/Issue131.py
+++ b/tests/Issue131.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue131(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/pull/133
diff --git a/tests/Issue133.py b/tests/Issue133.py
index 94ecd768..4b92359b 100644
--- a/tests/Issue133.py
+++ b/tests/Issue133.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue133(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/pull/133
diff --git a/tests/Issue134.py b/tests/Issue134.py
index a66ec153..3a820034 100644
--- a/tests/Issue134.py
+++ b/tests/Issue134.py
@@ -26,7 +26,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 import github
 
 
diff --git a/tests/Issue139.py b/tests/Issue139.py
index bf9be293..1196bdb6 100644
--- a/tests/Issue139.py
+++ b/tests/Issue139.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue139(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/issues/139
diff --git a/tests/Issue140.py b/tests/Issue140.py
index 23935adf..a9c061b7 100644
--- a/tests/Issue140.py
+++ b/tests/Issue140.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue140(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/issues/140
diff --git a/tests/Issue142.py b/tests/Issue142.py
index d32904e8..0bf555ec 100644
--- a/tests/Issue142.py
+++ b/tests/Issue142.py
@@ -25,6 +25,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import unittest
 import github
 
diff --git a/tests/Issue158.py b/tests/Issue158.py
index 63acaf22..e0b3ff45 100644
--- a/tests/Issue158.py
+++ b/tests/Issue158.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 import github
 
 
diff --git a/tests/Issue174.py b/tests/Issue174.py
index 852eb072..cec6beaa 100644
--- a/tests/Issue174.py
+++ b/tests/Issue174.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue174(Framework.TestCase):
diff --git a/tests/Issue214.py b/tests/Issue214.py
index 1144c1d4..7753357f 100644
--- a/tests/Issue214.py
+++ b/tests/Issue214.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue214(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/issues/214
diff --git a/tests/Issue216.py b/tests/Issue216.py
index 6f734c1b..04e2d959 100644
--- a/tests/Issue216.py
+++ b/tests/Issue216.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 # Replay data forged by capitalizing headers from PaginatedList.setUp.txt and PaginatedList.testIteration.txt
diff --git a/tests/Issue278.py b/tests/Issue278.py
index 92c17d74..be3217c5 100644
--- a/tests/Issue278.py
+++ b/tests/Issue278.py
@@ -24,7 +24,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 # Replay data forged by adding nulls to PaginatedList.setUp.txt and PaginatedList.testIteration.txt
diff --git a/tests/Issue33.py b/tests/Issue33.py
index 7ce5c3bd..175321ed 100644
--- a/tests/Issue33.py
+++ b/tests/Issue33.py
@@ -27,7 +27,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue33(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/issues/33
diff --git a/tests/Issue494.py b/tests/Issue494.py
index 28340612..0d59087d 100644
--- a/tests/Issue494.py
+++ b/tests/Issue494.py
@@ -23,7 +23,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue494(Framework.TestCase):
diff --git a/tests/Issue50.py b/tests/Issue50.py
index 66bc1ab3..f9bb2894 100644
--- a/tests/Issue50.py
+++ b/tests/Issue50.py
@@ -27,7 +27,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue50(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/issues/50
diff --git a/tests/Issue54.py b/tests/Issue54.py
index e92ced02..89ce8651 100644
--- a/tests/Issue54.py
+++ b/tests/Issue54.py
@@ -27,9 +27,10 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
-import Framework
+from . import Framework
 
 
 class Issue54(Framework.TestCase):
diff --git a/tests/Issue572.py b/tests/Issue572.py
index a52cf497..85bbd9ae 100644
--- a/tests/Issue572.py
+++ b/tests/Issue572.py
@@ -22,7 +22,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import github
 
diff --git a/tests/Issue80.py b/tests/Issue80.py
index 2741f703..f1850a6e 100644
--- a/tests/Issue80.py
+++ b/tests/Issue80.py
@@ -27,9 +27,10 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github
 
-import Framework
+from . import Framework
 
 
 class Issue80(Framework.BasicTestCase):  # https://github.com/jacquev6/PyGithub/issues/80
diff --git a/tests/Issue823.py b/tests/Issue823.py
index 352b1f37..d4145b9d 100644
--- a/tests/Issue823.py
+++ b/tests/Issue823.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue823(Framework.TestCase):
diff --git a/tests/Issue87.py b/tests/Issue87.py
index 93cab3b2..11b8ee0f 100644
--- a/tests/Issue87.py
+++ b/tests/Issue87.py
@@ -27,7 +27,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue87(Framework.TestCase):  # https://github.com/jacquev6/PyGithub/issues/87
diff --git a/tests/Issue937.py b/tests/Issue937.py
index d5d3fa19..88e91bc1 100644
--- a/tests/Issue937.py
+++ b/tests/Issue937.py
@@ -21,7 +21,8 @@
 # along with PyGithub. If not, see <http://www.gnu.org/licenses/>.             #
 #                                                                              #
 ################################################################################
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue937(Framework.TestCase):
diff --git a/tests/Issue945.py b/tests/Issue945.py
index ee758a74..1fd49351 100644
--- a/tests/Issue945.py
+++ b/tests/Issue945.py
@@ -22,7 +22,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Issue945(Framework.TestCase):  # https://github.com/PyGithub/PyGithub/issues/945
diff --git a/tests/IssueComment.py b/tests/IssueComment.py
index bfee2078..c0059de4 100644
--- a/tests/IssueComment.py
+++ b/tests/IssueComment.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/IssueEvent.py b/tests/IssueEvent.py
index 03f2d877..ff628586 100644
--- a/tests/IssueEvent.py
+++ b/tests/IssueEvent.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/Label.py b/tests/Label.py
index 81d4f091..0628c7ea 100644
--- a/tests/Label.py
+++ b/tests/Label.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Label(Framework.TestCase):
diff --git a/tests/License.py b/tests/License.py
index 1ad851f7..03b35390 100644
--- a/tests/License.py
+++ b/tests/License.py
@@ -22,7 +22,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class License(Framework.TestCase):
diff --git a/tests/Logging_.py b/tests/Logging_.py
index 887286d1..7bbc6199 100644
--- a/tests/Logging_.py
+++ b/tests/Logging_.py
@@ -29,12 +29,13 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import logging
 import sys
 
 import github
 
-import Framework
+from . import Framework
 
 python2 = sys.hexversion < 0x03000000
 
diff --git a/tests/Markdown.py b/tests/Markdown.py
index 722b81ba..733f611c 100644
--- a/tests/Markdown.py
+++ b/tests/Markdown.py
@@ -27,7 +27,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Markdown(Framework.TestCase):
diff --git a/tests/Migration.py b/tests/Migration.py
index c28f1e24..0d71507f 100644
--- a/tests/Migration.py
+++ b/tests/Migration.py
@@ -47,7 +47,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import github
 import datetime
diff --git a/tests/Milestone.py b/tests/Milestone.py
index 4654569f..5af992a8 100644
--- a/tests/Milestone.py
+++ b/tests/Milestone.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/NamedUser.py b/tests/NamedUser.py
index 6ac953c0..650eb68b 100644
--- a/tests/NamedUser.py
+++ b/tests/NamedUser.py
@@ -31,7 +31,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/Notification.py b/tests/Notification.py
index 84b623e2..103b7c75 100644
--- a/tests/Notification.py
+++ b/tests/Notification.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Notification(Framework.TestCase):
diff --git a/tests/Organization.py b/tests/Organization.py
index db55939f..be8bf2ac 100644
--- a/tests/Organization.py
+++ b/tests/Organization.py
@@ -34,9 +34,10 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import github
 
-import Framework
+from . import Framework
 
 import datetime
 
diff --git a/tests/OrganizationHasInMembers.py b/tests/OrganizationHasInMembers.py
index 384cfb2a..270d36c8 100644
--- a/tests/OrganizationHasInMembers.py
+++ b/tests/OrganizationHasInMembers.py
@@ -23,7 +23,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class OrganizationHasInMembers(Framework.TestCase):
diff --git a/tests/PaginatedList.py b/tests/PaginatedList.py
index 48f22906..4c66f559 100644
--- a/tests/PaginatedList.py
+++ b/tests/PaginatedList.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 from github.PaginatedList import PaginatedList as PaginatedListImpl
 
 
@@ -135,7 +136,7 @@ class PaginatedList(Framework.TestCase):
         self.assertEqual(len(list(self.repo.get_issues())), 456)
 
     def testCustomPerPageWithNoUrlParams(self):
-        import CommitComment  # Don't polute github.tests namespace, it would conflict with github.tests.CommitComment
+        from . import CommitComment  # Don't polute github.tests namespace, it would conflict with github.tests.CommitComment
         self.g.per_page = 100
         PaginatedListImpl(
             CommitComment.CommitComment,
diff --git a/tests/Persistence.py b/tests/Persistence.py
index ddf939df..4a9d8bfc 100644
--- a/tests/Persistence.py
+++ b/tests/Persistence.py
@@ -26,7 +26,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 import github
 
 from io import BytesIO as IO
diff --git a/tests/Project.py b/tests/Project.py
index ed9030f8..a7c5e629 100644
--- a/tests/Project.py
+++ b/tests/Project.py
@@ -22,7 +22,8 @@
 #                                                                              #
 # ##############################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 import github
 
 
diff --git a/tests/PullRequest.py b/tests/PullRequest.py
index b691079b..4559372c 100644
--- a/tests/PullRequest.py
+++ b/tests/PullRequest.py
@@ -31,7 +31,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/PullRequestComment.py b/tests/PullRequestComment.py
index 735cbc42..ea74ea94 100644
--- a/tests/PullRequestComment.py
+++ b/tests/PullRequestComment.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/PullRequestFile.py b/tests/PullRequestFile.py
index 502d08fe..92cc090e 100644
--- a/tests/PullRequestFile.py
+++ b/tests/PullRequestFile.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class PullRequestFile(Framework.TestCase):
diff --git a/tests/PullRequestReview.py b/tests/PullRequestReview.py
index 4349889f..397c9bd7 100644
--- a/tests/PullRequestReview.py
+++ b/tests/PullRequestReview.py
@@ -26,7 +26,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/RateLimiting.py b/tests/RateLimiting.py
index 2b75f9b6..958c6aad 100644
--- a/tests/RateLimiting.py
+++ b/tests/RateLimiting.py
@@ -28,9 +28,10 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import datetime
 
-import Framework
+from . import Framework
 
 
 class RateLimiting(Framework.TestCase):
diff --git a/tests/RawData.py b/tests/RawData.py
index fca9dc63..6e578d2b 100644
--- a/tests/RawData.py
+++ b/tests/RawData.py
@@ -25,7 +25,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import github.NamedUser
 
diff --git a/tests/Reaction.py b/tests/Reaction.py
index f301c879..e7244e5a 100644
--- a/tests/Reaction.py
+++ b/tests/Reaction.py
@@ -23,7 +23,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/Repository.py b/tests/Repository.py
index 86ce1649..af77ed64 100644
--- a/tests/Repository.py
+++ b/tests/Repository.py
@@ -47,7 +47,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import github
 import datetime
diff --git a/tests/RepositoryKey.py b/tests/RepositoryKey.py
index 6f6e09ae..866c1c1d 100644
--- a/tests/RepositoryKey.py
+++ b/tests/RepositoryKey.py
@@ -31,7 +31,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/RequiredPullRequestReviews.py b/tests/RequiredPullRequestReviews.py
index aa253e1f..501be3b4 100644
--- a/tests/RequiredPullRequestReviews.py
+++ b/tests/RequiredPullRequestReviews.py
@@ -22,7 +22,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class RequiredPullRequestReviews(Framework.TestCase):
diff --git a/tests/RequiredStatusChecks.py b/tests/RequiredStatusChecks.py
index c1a7634f..47a3141e 100644
--- a/tests/RequiredStatusChecks.py
+++ b/tests/RequiredStatusChecks.py
@@ -22,7 +22,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class RequiredStatusChecks(Framework.TestCase):
diff --git a/tests/Retry.py b/tests/Retry.py
index 79e6f284..1d5e2486 100644
--- a/tests/Retry.py
+++ b/tests/Retry.py
@@ -25,10 +25,11 @@
 # along with PyGithub. If not, see <http://www.gnu.org/licenses/>.             #
 #                                                                              #
 ################################################################################
+from __future__ import absolute_import
 import urllib3
 from httpretty import httpretty
 
-import Framework
+from . import Framework
 
 import requests
 
diff --git a/tests/Search.py b/tests/Search.py
index 8d45b6f2..31553fe3 100644
--- a/tests/Search.py
+++ b/tests/Search.py
@@ -26,7 +26,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 import sys
 
 atLeastPython3 = sys.hexversion >= 0x03000000
diff --git a/tests/SourceImport.py b/tests/SourceImport.py
index 0c2c7c56..355eed86 100644
--- a/tests/SourceImport.py
+++ b/tests/SourceImport.py
@@ -22,7 +22,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class SourceImport(Framework.TestCase):
diff --git a/tests/Tag.py b/tests/Tag.py
index 589a3d0e..ca0f3ffe 100644
--- a/tests/Tag.py
+++ b/tests/Tag.py
@@ -28,7 +28,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Tag(Framework.TestCase):
diff --git a/tests/Team.py b/tests/Team.py
index a96f0372..c14f2e40 100644
--- a/tests/Team.py
+++ b/tests/Team.py
@@ -34,7 +34,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class Team(Framework.TestCase):
diff --git a/tests/Time.py b/tests/Time.py
index 4743eaa3..a63f7986 100644
--- a/tests/Time.py
+++ b/tests/Time.py
@@ -20,6 +20,7 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 from datetime import timedelta, tzinfo
 
 
diff --git a/tests/Traffic.py b/tests/Traffic.py
index 9fc398d3..431a1215 100644
--- a/tests/Traffic.py
+++ b/tests/Traffic.py
@@ -26,7 +26,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 import datetime
 
diff --git a/tests/UserKey.py b/tests/UserKey.py
index c51249b5..4c583c70 100644
--- a/tests/UserKey.py
+++ b/tests/UserKey.py
@@ -29,7 +29,8 @@
 #                                                                              #
 ################################################################################
 
-import Framework
+from __future__ import absolute_import
+from . import Framework
 
 
 class UserKey(Framework.TestCase):
diff --git a/tests/__main__.py b/tests/__main__.py
index cdd9dcbc..132a5d94 100644
--- a/tests/__main__.py
+++ b/tests/__main__.py
@@ -28,10 +28,11 @@
 #                                                                              #
 ################################################################################
 
+from __future__ import absolute_import
 import sys
 import unittest
-import Framework
-import AllTests
+from . import Framework
+from . import AllTests
 
 
 def main(argv):