TST - Moved NonDictMapping test util class to pandas/util/testing.py

TST - Added a test of constructing a series from NonDictMapping

Author: ohad83

pandas/tests/series/test_apply.py

@@ -1,4 +1,4 @@
-from collections import Counter, OrderedDict, abc, defaultdict
+from collections import Counter, OrderedDict, defaultdict
 from itertools import chain
 
 import numpy as np
@@ -615,46 +615,21 @@ class DictWithoutMissing(dict):
     def test_map_abc_mapping(self):
         # https://github.com/pandas-dev/pandas/issues/29733
         # Check collections.abc.Mapping support as mapper for Series.map
-        class NonDictMapping(abc.Mapping):
-            def __init__(self):
-                self._data = {3: "three"}
-
-            def __getitem__(self, key):
-                return self._data.__getitem__(key)
-
-            def __iter__(self):
-                return self._data.__iter__()
-
-            def __len__(self):
-                return self._data.__len__()
-
         s = Series([1, 2, 3])
-        not_a_dictionary = NonDictMapping()
+        not_a_dictionary = tm.TestNonDictMapping({3: "three"})
         result = s.map(not_a_dictionary)
         expected = Series([np.nan, np.nan, "three"])
         tm.assert_series_equal(result, expected)
 
     def test_map_abc_mapping_with_missing(self):
         # https://github.com/pandas-dev/pandas/issues/29733
         # Check collections.abc.Mapping support as mapper for Series.map
-        class NonDictMappingWithMissing(abc.Mapping):
-            def __init__(self):
-                self._data = {3: "three"}
-
-            def __getitem__(self, key):
-                return self._data.__getitem__(key)
-
-            def __iter__(self):
-                return self._data.__iter__()
-
-            def __len__(self):
-                return self._data.__len__()
-
+        class NonDictMappingWithMissing(tm.TestNonDictMapping):
             def __missing__(self, key):
                 return "missing"
 
         s = Series([1, 2, 3])
-        not_a_dictionary = NonDictMappingWithMissing()
+        not_a_dictionary = NonDictMappingWithMissing({3: "three"})
         result = s.map(not_a_dictionary)
         # __missing__ is a dict concept, not a Mapping concept,
         # so it should not change the result!

pandas/tests/series/test_constructors.py

@@ -1081,6 +1081,14 @@ def create_data(constructor):
         tm.assert_series_equal(result_datetime, expected)
         tm.assert_series_equal(result_Timestamp, expected)
 
+    def test_constructor_mapping(self):
+        # GH 29788
+        ndm = tm.TestNonDictMapping({3: "three"})
+        result = Series(ndm)
+        expected = Series(["three"], index=[3])
+
+        tm.assert_series_equal(result, expected)
+
     def test_constructor_list_of_tuples(self):
         data = [(1, 1), (2, 2), (2, 3)]
         s = Series(data)

pandas/util/testing.py

@@ -1,5 +1,5 @@
 import bz2
-from collections import Counter
+from collections import Counter, abc
 from contextlib import contextmanager
 from datetime import datetime
 from functools import wraps
@@ -2121,6 +2121,20 @@ def __init__(self, *args, **kwargs):
         dict.__init__(self, *args, **kwargs)
 
 
+class TestNonDictMapping(abc.Mapping):
+    def __init__(self, underlying_dict):
+        self._data = underlying_dict
+
+    def __getitem__(self, key):
+        return self._data.__getitem__(key)
+
+    def __iter__(self):
+        return self._data.__iter__()
+
+    def __len__(self):
+        return self._data.__len__()
+
+
 def optional_args(decorator):
     """allows a decorator to take optional positional and keyword arguments.
     Assumes that taking a single, callable, positional argument means that