Use six.PY3 instead of twisted.python.compat._PY3

#288

src/treq/client.py

@@ -5,10 +5,12 @@
 
 from io import BytesIO
 
+from six import PY3
+
 from twisted.internet.interfaces import IProtocol
 from twisted.internet.defer import Deferred
 from twisted.python.components import proxyForInterface
-from twisted.python.compat import _PY3, unicode
+from twisted.python.compat import unicode
 from twisted.python.filepath import FilePath
 from hyperlink import DecodedURL, EncodedURL
 
@@ -33,7 +35,7 @@
 from treq.response import _Response
 from requests.cookies import cookiejar_from_dict, merge_cookies
 
-if _PY3:
+if PY3:
     from urllib.parse import urlencode as _urlencode
 
     def urlencode(query, doseq):
@@ -377,7 +379,7 @@ def _guess_content_type(filename):
 registerAdapter(_from_bytes, bytes, IBodyProducer)
 registerAdapter(_from_file, BytesIO, IBodyProducer)
 
-if not _PY3:
+if not PY3:
     from StringIO import StringIO
     registerAdapter(_from_file, StringIO, IBodyProducer)
     # Suppress lint failure on Python 3.

src/treq/multipart.py

@@ -7,13 +7,15 @@
 from io import BytesIO
 from contextlib import closing
 
+from six import PY3
+
 from twisted.internet import defer, task
-from twisted.python.compat import unicode, _PY3
+from twisted.python.compat import unicode
 from twisted.web.iweb import UNKNOWN_LENGTH, IBodyProducer
 
 from zope.interface import implementer
 
-if _PY3:
+if PY3:
     long = int
 
 CRLF = b"\r\n"

src/treq/test/test_multipart.py

@@ -10,14 +10,16 @@
 from twisted.trial import unittest
 from zope.interface.verify import verifyObject
 
+from six import PY3
+
 from twisted.python import compat
 from twisted.internet import task
 from twisted.web.client import FileBodyProducer
 from twisted.web.iweb import UNKNOWN_LENGTH, IBodyProducer
 
 from treq.multipart import MultiPartProducer, _LengthConsumer
 
-if compat._PY3:
+if PY3:
     long = int
     unicode = compat.unicode
 

src/treq/test/test_testing.py

@@ -6,14 +6,13 @@
 
 from mock import ANY
 
-from six import text_type, binary_type
+from six import text_type, binary_type, PY3
 
 from twisted.trial.unittest import TestCase
 from twisted.web.client import ResponseFailed
 from twisted.web.error import SchemeNotSupported
 from twisted.web.resource import Resource
 from twisted.web.server import NOT_DONE_YET
-from twisted.python.compat import _PY3
 
 import treq
 
@@ -307,7 +306,7 @@ def test_repr(self):
         """
         :obj:`HasHeaders` returns a nice string repr.
         """
-        if _PY3:
+        if PY3:
             reprOutput = "HasHeaders({b'a': [b'b']})"
         else:
             reprOutput = "HasHeaders({'a': ['b']})"