Use collections.abc on Python 3

Starting before Python 3.3 (which is the oldest version we support),
the ABCs for collections are located at collections.abc, but aliased
into collections.

Starting in Python 3.7, referring to them using the aliases produces
DeprecationWarnings, which breaks our users.  The alias will be
removed entirely in Python 3.8.

Signed-off-by: Christian Heimes <cheimes@redhat.com>
[rharwood@redhat.com: Write commit message, update style on checks]
Merges: #154

Author: tiran

gssapi/names.py

@@ -1,12 +1,16 @@
-import collections
-
 import six
 
 from gssapi.raw import names as rname
 from gssapi.raw import NameType
 from gssapi.raw import named_tuples as tuples
 from gssapi import _utils
 
+if six.PY2:
+    from collections import MutableMapping, Iterable
+else:
+    from collections.abc import MutableMapping, Iterable
+
+
 rname_rfc6680 = _utils.import_gssapi_extension('rfc6680')
 rname_rfc6680_comp_oid = _utils.import_gssapi_extension('rfc6680_comp_oid')
 
@@ -313,7 +317,7 @@ def attributes(self):
         return self._attr_obj
 
 
-class _NameAttributeMapping(collections.MutableMapping):
+class _NameAttributeMapping(MutableMapping):
 
     """Provides dict-like access to RFC 6680 Name attributes."""
     def __init__(self, name):
@@ -345,7 +349,7 @@ def __setitem__(self, key, value):
             complete = False
 
         if (isinstance(value, (six.string_types, bytes)) or
-                not isinstance(value, collections.Iterable)):
+                not isinstance(value, Iterable)):
             # NB(directxman12): this allows us to easily assign a single
             # value, since that's a common case
             value = [value]

gssapi/raw/ext_dce.pyx

@@ -9,12 +9,18 @@ from gssapi.raw.sec_contexts cimport SecurityContext
 from gssapi.raw.misc import GSSError
 from gssapi.raw import types as gssapi_types
 from gssapi.raw.named_tuples import IOVUnwrapResult, WrapResult, UnwrapResult
-from collections import namedtuple, Sequence
+from collections import namedtuple
 
 from enum import IntEnum
 import six
 from gssapi.raw._enum_extensions import ExtendableEnum
 
+if six.PY2:
+    from collections import Sequence
+else:
+    from collections.abc import Sequence
+
+
 cdef extern from "python_gssapi_ext.h":
     # NB(directxman12): this wiki page has a different argument order
     #                   than the header file, and uses size_t instead of int

gssapi/raw/types.pyx

@@ -13,6 +13,11 @@ import numbers
 import operator
 import six
 
+if six.PY2:
+    from collections import MutableSet
+else:
+    from collections.abc import MutableSet
+
 
 class NameType(object):
     """
@@ -106,7 +111,7 @@ class MechType(object):
     # these are added in by the individual mechanism files on import
 
 
-class GenericFlagSet(collections.MutableSet):
+class GenericFlagSet(MutableSet):
     """A set backed by a 32-bit integer
 
     This is a set backed by a 32 bit integer.

gssapi/tests/test_raw.py

@@ -1,16 +1,21 @@
-import collections
 import copy
 import os
 import socket
 import unittest
 
+import six
 import should_be.all  # noqa
 
 import gssapi.raw as gb
 import gssapi.raw.misc as gbmisc
 import k5test.unit as ktu
 import k5test as kt
 
+if six.PY2:
+    from collections import Set
+else:
+    from collections.abc import Set
+
 
 TARGET_SERVICE_NAME = b'host'
 FQDN = socket.getfqdn().encode('utf-8')
@@ -355,7 +360,7 @@ def test_inquire_context(self):
         mech_type.should_be(gb.MechType.kerberos)
 
         flags.shouldnt_be_none()
-        flags.should_be_a(collections.Set)
+        flags.should_be_a(Set)
         flags.shouldnt_be_empty()
 
         local_est.should_be_a(bool)
@@ -1084,7 +1089,7 @@ def test_basic_init_default_ctx(self):
 
         out_mech_type.should_be(gb.MechType.kerberos)
 
-        out_req_flags.should_be_a(collections.Set)
+        out_req_flags.should_be_a(Set)
         out_req_flags.should_be_at_least_length(2)
 
         out_token.shouldnt_be_empty()
@@ -1139,7 +1144,7 @@ def test_basic_accept_context_no_acceptor_creds(self):
 
         out_token.shouldnt_be_empty()
 
-        out_req_flags.should_be_a(collections.Set)
+        out_req_flags.should_be_a(Set)
         out_req_flags.should_be_at_least_length(2)
 
         out_ttl.should_be_greater_than(0)
@@ -1167,7 +1172,7 @@ def test_basic_accept_context(self):
 
         out_token.shouldnt_be_empty()
 
-        out_req_flags.should_be_a(collections.Set)
+        out_req_flags.should_be_a(Set)
         out_req_flags.should_be_at_least_length(2)
 
         out_ttl.should_be_greater_than(0)

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py27,py33,py34,py35
+envlist = py27,py33,py34,py35,py36,py37
 
 [testenv]
 whitelist_externals=bash