Update per comment jreback

Author: alimcmaster1

pandas/core/generic.py

@@ -3140,12 +3140,14 @@ def _drop_axis(self, labels, axis, level=None, errors='raise'):
                 new_axis = axis.drop(labels, errors=errors)
             result = self.reindex(**{axis_name: new_axis})
 
+        # Case for non-unique axis
         else:
             labels = _ensure_object(com._index_labels_to_array(labels))
             if level is not None:
                 if not isinstance(axis, MultiIndex):
                     raise AssertionError('axis must be a MultiIndex')
                 indexer = ~axis.get_level_values(level).isin(labels)
+
                 # GH 18561 MultiIndex.drop should raise if label is absent
                 if errors == 'raise' and indexer.all():
                     raise KeyError('{} not found in axis'.format(labels))

pandas/tests/frame/test_axis_select_reindex.py

@@ -1151,3 +1151,24 @@ def test_raise_on_drop_duplicate_index(self, actual):
         expected_no_err = actual.T.drop('c', axis=1, level=level,
                                         errors='ignore')
         assert_frame_equal(expected_no_err.T, actual)
+
+    @pytest.mark.parametrize('index, drop_labels', [
+        ([1, 2, 3], []),
+        ([1, 1, 2], []),
+        ([1, 2, 3], [2]),
+        ([1, 1, 3], [1]),
+    ])
+    def test_drop_empty_list(self, index, drop_labels):
+        # GH 21494
+        expected_index = [i for i in index if i not in drop_labels]
+        frame = pd.DataFrame(index=index).drop(drop_labels)
+        tm.assert_frame_equal(frame, pd.DataFrame(index=expected_index))
+
+    @pytest.mark.parametrize('index, drop_labels', [
+        ([1, 2, 3], [1, 4]),
+        ([1, 2, 2], [1, 4]),
+    ])
+    def test_drop_non_empty_list(self, index, drop_labels):
+        # GH 21494
+        with tm.assert_raises_regex(KeyError, 'not found in axis'):
+            pd.DataFrame(index=index).drop(drop_labels)

pandas/tests/frame/test_indexing.py

@@ -3515,24 +3515,3 @@ def test_functions_no_warnings(self):
         with tm.assert_produces_warning(False):
             df['group'] = pd.cut(df.value, range(0, 105, 10), right=False,
                                  labels=labels)
-
-    @pytest.mark.parametrize('index, drop_labels', [
-        ([1, 2, 3], []),
-        ([1, 1, 2], []),
-        ([1, 2, 3], [2]),
-        ([1, 1, 3], [1]),
-    ])
-    def test_drop_empty_list(self, index, drop_labels):
-        # GH 21494
-        expected_index = [i for i in index if i not in drop_labels]
-        frame = pd.DataFrame(index=index).drop(drop_labels)
-        tm.assert_frame_equal(frame, pd.DataFrame(index=expected_index))
-
-    @pytest.mark.parametrize('index, drop_labels', [
-        ([1, 2, 3], [1, 4]),
-        ([1, 2, 2], [1, 4]),
-    ])
-    def test_drop_non_empty_list(self, index, drop_labels):
-        # GH 21494
-        with tm.assert_raises_regex(KeyError, 'not found in axis'):
-            pd.DataFrame(index=index).drop(drop_labels)

pandas/tests/indexes/test_base.py

@@ -1565,6 +1565,79 @@ def test_drop_tuple(self, values, to_drop):
         for drop_me in to_drop[1], [to_drop[1]]:
             pytest.raises(KeyError, removed.drop, drop_me)
 
+    def test_drop_unique_and_non_unique_index(self):
+        # unique
+        s = Series([1, 2], index=['one', 'two'])
+        expected = Series([1], index=['one'])
+        result = s.drop(['two'])
+        tm.assert_series_equal(result, expected)
+        result = s.drop('two', axis='rows')
+        tm.assert_series_equal(result, expected)
+
+        # non-unique
+        # GH 5248
+        s = Series([1, 1, 2], index=['one', 'two', 'one'])
+        expected = Series([1, 2], index=['one', 'one'])
+        result = s.drop(['two'], axis=0)
+        tm.assert_series_equal(result, expected)
+        result = s.drop('two')
+        tm.assert_series_equal(result, expected)
+
+        expected = Series([1], index=['two'])
+        result = s.drop(['one'])
+        tm.assert_series_equal(result, expected)
+        result = s.drop('one')
+        tm.assert_series_equal(result, expected)
+
+        # single string/tuple-like
+        s = Series(range(3), index=list('abc'))
+        pytest.raises(KeyError, s.drop, 'bc')
+        pytest.raises(KeyError, s.drop, ('a',))
+
+        # errors='ignore'
+        s = Series(range(3), index=list('abc'))
+        result = s.drop('bc', errors='ignore')
+        tm.assert_series_equal(result, s)
+        result = s.drop(['a', 'd'], errors='ignore')
+        expected = s.iloc[1:]
+        tm.assert_series_equal(result, expected)
+
+        # bad axis
+        pytest.raises(ValueError, s.drop, 'one', axis='columns')
+
+        # GH 8522
+        s = Series([2, 3], index=[True, False])
+        assert s.index.is_object()
+        result = s.drop(True)
+        expected = Series([3], index=[False])
+        tm.assert_series_equal(result, expected)
+
+        # GH 16877
+        s = Series([2, 3], index=[0, 1])
+        with tm.assert_raises_regex(KeyError, 'not found in axis'):
+            s.drop([False, True])
+
+    @pytest.mark.parametrize('index, drop_labels', [
+        ([1, 2, 3], []),
+        ([1, 1, 2], []),
+        ([1, 2, 3], [2]),
+        ([1, 1, 3], [1]),
+    ])
+    def test_drop_empty_list(self, index, drop_labels):
+        # GH 21494
+        expected_index = [i for i in index if i not in drop_labels]
+        series = pd.Series(index=index).drop(drop_labels)
+        tm.assert_series_equal(series, pd.Series(index=expected_index))
+
+    @pytest.mark.parametrize('index, drop_labels', [
+        ([1, 2, 3], [1, 4]),
+        ([1, 2, 2], [1, 4]),
+    ])
+    def test_drop_non_empty_list(self, index, drop_labels):
+        # GH 21494
+        with tm.assert_raises_regex(KeyError, 'not found in axis'):
+            pd.Series(index=index).drop(drop_labels)
+
     @pytest.mark.parametrize("method,expected", [
         ('intersection', np.array([(1, 'A'), (2, 'A'), (1, 'B'), (2, 'B')],
                                   dtype=[('num', int), ('let', 'a1')])),

pandas/tests/series/indexing/test_alter_index.py

@@ -461,79 +461,3 @@ def test_rename():
     assert_series_equal(result, expected)
 
     assert result.name == expected.name
-
-
-def test_drop():
-    # unique
-    s = Series([1, 2], index=['one', 'two'])
-    expected = Series([1], index=['one'])
-    result = s.drop(['two'])
-    assert_series_equal(result, expected)
-    result = s.drop('two', axis='rows')
-    assert_series_equal(result, expected)
-
-    # non-unique
-    # GH 5248
-    s = Series([1, 1, 2], index=['one', 'two', 'one'])
-    expected = Series([1, 2], index=['one', 'one'])
-    result = s.drop(['two'], axis=0)
-    assert_series_equal(result, expected)
-    result = s.drop('two')
-    assert_series_equal(result, expected)
-
-    expected = Series([1], index=['two'])
-    result = s.drop(['one'])
-    assert_series_equal(result, expected)
-    result = s.drop('one')
-    assert_series_equal(result, expected)
-
-    # single string/tuple-like
-    s = Series(range(3), index=list('abc'))
-    pytest.raises(KeyError, s.drop, 'bc')
-    pytest.raises(KeyError, s.drop, ('a',))
-
-    # errors='ignore'
-    s = Series(range(3), index=list('abc'))
-    result = s.drop('bc', errors='ignore')
-    assert_series_equal(result, s)
-    result = s.drop(['a', 'd'], errors='ignore')
-    expected = s.iloc[1:]
-    assert_series_equal(result, expected)
-
-    # bad axis
-    pytest.raises(ValueError, s.drop, 'one', axis='columns')
-
-    # GH 8522
-    s = Series([2, 3], index=[True, False])
-    assert s.index.is_object()
-    result = s.drop(True)
-    expected = Series([3], index=[False])
-    assert_series_equal(result, expected)
-
-    # GH 16877
-    s = Series([2, 3], index=[0, 1])
-    with tm.assert_raises_regex(KeyError, 'not found in axis'):
-        s.drop([False, True])
-
-
-@pytest.mark.parametrize('index, drop_labels', [
-    ([1, 2, 3], []),
-    ([1, 1, 2], []),
-    ([1, 2, 3], [2]),
-    ([1, 1, 3], [1]),
-])
-def test_drop_empty_list(index, drop_labels):
-    # GH 21494
-    expected_index = [i for i in index if i not in drop_labels]
-    series = pd.Series(index=index).drop(drop_labels)
-    tm.assert_series_equal(series, pd.Series(index=expected_index))
-
-
-@pytest.mark.parametrize('index, drop_labels', [
-    ([1, 2, 3], [1, 4]),
-    ([1, 2, 2], [1, 4]),
-])
-def test_drop_non_empty_list(index, drop_labels):
-    # GH 21494
-    with tm.assert_raises_regex(KeyError, 'not found in axis'):
-        pd.Series(index=index).drop(drop_labels)