no need to redefine PY3 - six already has it

mongoengine/base/document.py

@@ -19,7 +19,6 @@ from mongoengine.base.fields import ComplexBaseField
 from mongoengine.common import _import_class
 from mongoengine.errors import (FieldDoesNotExist, InvalidDocumentError,
                                 LookUpError, OperationError, ValidationError)
-from mongoengine.python_support import PY3
 
 __all__ = ('BaseDocument',)
 
@@ -256,7 +255,7 @@ class BaseDocument(object):
     def __str__(self):
         # TODO this could be simpler?
         if hasattr(self, '__unicode__'):
-            if PY3:
+            if six.PY3:
                 return self.__unicode__()
             else:
                 return six.text_type(self).encode('utf-8')

mongoengine/base/metaclasses.py

@@ -1,10 +1,11 @@
 import warnings
 
+import six
+
 from mongoengine.base.common import _document_registry
 from mongoengine.base.fields import BaseField, ComplexBaseField, ObjectIdField
 from mongoengine.common import _import_class
 from mongoengine.errors import InvalidDocumentError
-from mongoengine.python_support import PY3
 from mongoengine.queryset import (DO_NOTHING, DoesNotExist,
                                   MultipleObjectsReturned,
                                   QuerySetManager)
@@ -159,7 +160,7 @@ class DocumentMetaclass(type):
         # module continues to use im_func and im_self, so the code below
         # copies __func__ into im_func and __self__ into im_self for
         # classmethod objects in Document derived classes.
-        if PY3:
+        if six.PY3:
             for val in new_class.__dict__.values():
                 if isinstance(val, classmethod):
                     f = val.__get__(new_class)

mongoengine/fields.py

@@ -30,7 +30,7 @@ from mongoengine.base import (BaseDocument, BaseField, ComplexBaseField,
 from mongoengine.connection import DEFAULT_CONNECTION_NAME, get_db
 from mongoengine.document import Document, EmbeddedDocument
 from mongoengine.errors import DoesNotExist, ValidationError
-from mongoengine.python_support import PY3, StringIO
+from mongoengine.python_support import StringIO
 from mongoengine.queryset import DO_NOTHING, QuerySet
 
 try:
@@ -1307,7 +1307,7 @@ class BinaryField(BaseField):
 
     def __set__(self, instance, value):
         """Handle bytearrays in python 3.1"""
-        if PY3 and isinstance(value, bytearray):
+        if six.PY3 and isinstance(value, bytearray):
             value = six.binary_type(value)
         return super(BinaryField, self).__set__(instance, value)
 
@@ -1722,7 +1722,7 @@ class ImageField(FileField):
         for att_name, att in extra_args.items():
             value = None
             if isinstance(att, (tuple, list)):
-                if PY3:
+                if six.PY3:
                     value = dict(itertools.zip_longest(params_size, att,
                                                        fillvalue=None))
                 else:

mongoengine/python_support.py

@@ -13,14 +13,11 @@ else:
     IS_PYMONGO_3 = True
 
 
-PY3 = sys.version_info[0] == 3
-
-
 # six.BytesIO resolves to StringIO.StringIO in Py2 and io.BytesIO in Py3.
 StringIO = six.BytesIO
 
 # Additionally for Py2, try to use the faster cStringIO, if available
-if not PY3:
+if not six.PY3:
     try:
         import cStringIO
     except ImportError:

tests/fields/fields.py

@@ -28,7 +28,6 @@ from mongoengine.connection import get_db
 from mongoengine.base import (BaseDict, BaseField, EmbeddedDocumentList,
                               _document_registry)
 from mongoengine.errors import NotRegistered, DoesNotExist
-from mongoengine.python_support import PY3
 
 __all__ = ("FieldTest", "EmbeddedDocumentListFieldTestCase")
 
@@ -653,7 +652,7 @@ class FieldTest(unittest.TestCase):
         self.assertNotEqual(log.date, d1)
         self.assertEqual(log.date, d2)
 
-        if not PY3:
+        if not six.PY3:
             # Pre UTC dates microseconds below 1000 are dropped
             # This does not seem to be true in PY3
             d1 = datetime.datetime(1969, 12, 31, 23, 59, 59, 999)

tests/queryset/queryset.py

@@ -9,13 +9,13 @@ from nose.plugins.skip import SkipTest
 import pymongo
 from pymongo.errors import ConfigurationError
 from pymongo.read_preferences import ReadPreference
-
+import six
 
 from mongoengine import *
 from mongoengine.connection import get_connection, get_db
 from mongoengine.context_managers import query_counter, switch_db
 from mongoengine.errors import InvalidQueryError
-from mongoengine.python_support import IS_PYMONGO_3, PY3
+from mongoengine.python_support import IS_PYMONGO_3
 from mongoengine.queryset import (DoesNotExist, MultipleObjectsReturned,
                                   QuerySet, QuerySetManager, queryset_manager)
 
@@ -4089,7 +4089,7 @@ class QuerySetTest(unittest.TestCase):
             "A0", "%s" % self.Person.objects.order_by('name').scalar('name').first())
         self.assertEqual(
             "A0", "%s" % self.Person.objects.scalar('name').order_by('name')[0])
-        if PY3:
+        if six.PY3:
             self.assertEqual("['A1', 'A2']", "%s" % self.Person.objects.order_by(
                 'age').scalar('name')[1:3])
             self.assertEqual("['A51', 'A52']", "%s" % self.Person.objects.order_by(
@@ -4107,7 +4107,7 @@ class QuerySetTest(unittest.TestCase):
 
         pks = self.Person.objects.order_by('age').scalar('pk')[1:3]
         names = self.Person.objects.scalar('name').in_bulk(list(pks)).values()
-        if PY3:
+        if six.PY3:
             expected = "['A1', 'A2']"
         else:
             expected = "[u'A1', u'A2']"