Switch to using six (#1189)

With the Python 2.7 deadline fast approaching, modernize the codebase
making use of the modernize module to switch to using six, as well as
other upcoming features, such as absolute imports . Stop using 2to3
for Travis, yay!

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)