change collections.abc import to fix deprecation warnings on python 3.7

_pytest/assertion/util.py

@@ -5,7 +5,7 @@
 import _pytest._code
 import py
 import six
-from collections import Sequence
+from ..compat import Sequence
 
 u = six.text_type
 

_pytest/compat.py

@@ -38,6 +38,14 @@
 PY36 = sys.version_info[:2] >= (3, 6)
 MODULE_NOT_FOUND_ERROR = 'ModuleNotFoundError' if PY36 else 'ImportError'
 
+if _PY3:
+    from collections.abc import MutableMapping as MappingMixin  # noqa
+    from collections.abc import Sequence  # noqa
+else:
+    # those raise DeprecationWarnings in Python >=3.7
+    from collections import MutableMapping as MappingMixin  # noqa
+    from collections import Sequence  # noqa
+
 
 def _format_args(func):
     return str(signature(func))

_pytest/mark/structures.py

@@ -1,13 +1,13 @@
-from collections import namedtuple, MutableMapping as MappingMixin
+import inspect
 import warnings
+from collections import namedtuple
 from operator import attrgetter
-import inspect
 
 import attr
-from ..deprecated import MARK_PARAMETERSET_UNPACKING
-from ..compat import NOTSET, getfslineno
 from six.moves import map
 
+from ..compat import NOTSET, getfslineno, MappingMixin
+from ..deprecated import MARK_PARAMETERSET_UNPACKING
 
 EMPTY_PARAMETERSET_OPTION = "empty_parameter_set_mark"
 

changelog/3339.trivial

@@ -0,0 +1 @@
+Import some modules from ``collections`` instead of ``collections.abc`` as the former modules trigger ``DeprecationWarning`` in Python 3.7.