ENH: df.loc accepts zerodim integer np.array, and add test

Author: tamuhey

Diff for: pandas/core/indexing.py

@@ -1857,6 +1857,7 @@ def _getitem_axis(self, key, axis=None):
         if axis is None:
             axis = self.axis or 0
 
+        key = item_from_zerodim(key)
         if is_iterator(key):
             key = list(key)
 

Diff for: pandas/tests/indexing/test_loc.py

@@ -765,3 +765,14 @@ def test_loc_setitem_empty_append_raises(self):
         msg = "cannot copy sequence with size 2 to array axis with dimension 0"
         with pytest.raises(ValueError, match=msg):
             df.loc[0:2, 'x'] = data
+
+    def test_indexing_zero_dim_np_array(self):
+        # GH24924
+        df = DataFrame([[1, 2], [3, 4]])
+
+        # should not raise an error
+        result = df.loc[np.array(0)]
+
+        # expected series
+        sr = pd.Series([1, 2], name=0)
+        tm.assert_series_equal(result, sr)