From da16545e6fbb46b1d57822fb720fa91ef4a46366 Mon Sep 17 00:00:00 2001
From: Frank Sachsenheim <funkyfuture@riseup.net>
Date: Wed, 3 Oct 2018 21:38:11 +0200
Subject: [PATCH] Imports abstract base classes from the platform module

Closes #450
---
 cerberus/platform.py  | 26 ++++++++++++++++++++++++++
 cerberus/schema.py    |  2 +-
 cerberus/utils.py     |  4 ++--
 cerberus/validator.py | 13 ++++++++++---
 4 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/cerberus/platform.py b/cerberus/platform.py
index eca9858d..66b1d5f0 100644
--- a/cerberus/platform.py
+++ b/cerberus/platform.py
@@ -12,3 +12,29 @@
 else:
     _str_type = str
     _int_types = (int,)
+
+
+if PYTHON_VERSION < 3.3:
+    from collections import (  # noqa: F401
+        Callable,
+        Container,
+        Hashable,
+        Iterable,
+        Mapping,
+        MutableMapping,
+        Sequence,
+        Set,
+        Sized,
+    )
+else:
+    from collections.abc import (  # noqa: F401
+        Callable,
+        Container,
+        Hashable,
+        Iterable,
+        Mapping,
+        MutableMapping,
+        Sequence,
+        Set,
+        Sized,
+    )
diff --git a/cerberus/schema.py b/cerberus/schema.py
index 6c865d87..4b18639c 100644
--- a/cerberus/schema.py
+++ b/cerberus/schema.py
@@ -1,6 +1,5 @@
 from __future__ import absolute_import
 
-from collections import Callable, Hashable, Mapping, MutableMapping, Sequence
 from copy import copy
 from warnings import warn
 
@@ -12,6 +11,7 @@
     mapping_hash,
     TypeDefinition,
 )
+from cerberus.platform import Callable, Hashable, Mapping, MutableMapping, Sequence
 
 
 class _Abort(Exception):
diff --git a/cerberus/utils.py b/cerberus/utils.py
index c0d157ad..a12ebfc5 100644
--- a/cerberus/utils.py
+++ b/cerberus/utils.py
@@ -1,8 +1,8 @@
 from __future__ import absolute_import
 
-from collections import Mapping, namedtuple, Sequence, Set
+from collections import namedtuple
 
-from cerberus.platform import _int_types, _str_type
+from cerberus.platform import _int_types, _str_type, Mapping, Sequence, Set
 
 
 TypeDefinition = namedtuple('TypeDefinition', 'name,included_types,excluded_types')
diff --git a/cerberus/validator.py b/cerberus/validator.py
index 17981e31..61bffa79 100644
--- a/cerberus/validator.py
+++ b/cerberus/validator.py
@@ -11,14 +11,22 @@
 from __future__ import absolute_import
 
 from ast import literal_eval
-from collections import Container, Hashable, Iterable, Mapping, Sequence, Sized
 from copy import copy
 from datetime import date, datetime
 import re
 from warnings import warn
 
 from cerberus import errors
-from cerberus.platform import _int_types, _str_type
+from cerberus.platform import (
+    _int_types,
+    _str_type,
+    Container,
+    Hashable,
+    Iterable,
+    Mapping,
+    Sequence,
+    Sized,
+)
 from cerberus.schema import (
     schema_registry,
     rules_set_registry,
@@ -27,7 +35,6 @@
 )
 from cerberus.utils import drop_item_from_tuple, readonly_classproperty, TypeDefinition
 
-
 toy_error_handler = errors.ToyErrorHandler()