BUG - Allow a mapper of type collections.abc.Mapping when using

Series.map

Author: ohad83

pandas/core/base.py

@@ -2,7 +2,7 @@
 Base and utility classes for pandas objects.
 """
 import builtins
-from collections import OrderedDict
+from collections import OrderedDict, abc
 import textwrap
 from typing import Dict, FrozenSet, List, Optional
 import warnings
@@ -1215,7 +1215,7 @@ def _map_values(self, mapper, na_action=None):
         # we can fastpath dict/Series to an efficient map
         # as we know that we are not going to have to yield
         # python types
-        if isinstance(mapper, dict):
+        if isinstance(mapper, abc.Mapping):
             if hasattr(mapper, "__missing__"):
                 # If a dictionary subclass defines a default value method,
                 # convert mapper to a lookup function (GH #15999).