ENH: df.iloc accepts zero dim integer np.array as int

Author: tamuhey

pandas/core/indexing.py

@@ -5,6 +5,7 @@
 import numpy as np
 
 from pandas._libs.indexing import _NDFrameIndexerBase
+from pandas._libs.lib import item_from_zerodim
 import pandas.compat as compat
 from pandas.compat import range, zip
 from pandas.errors import AbstractMethodError
@@ -2222,6 +2223,7 @@ def _getitem_axis(self, key, axis=None):
 
         # a single integer
         else:
+            key = item_from_zerodim(key)
             if not is_integer(key):
                 raise TypeError("Cannot index by location index with a "
                                 "non-integer key")

pandas/tests/indexing/test_iloc.py

@@ -675,3 +675,10 @@ def test_identity_slice_returns_new_object(self):
         # should also be a shallow copy
         original_series[:3] = [7, 8, 9]
         assert all(sliced_series[:3] == [7, 8, 9])
+
+    def test_indexing_zero_dim_np_array(self):
+        # GH24919
+        df = DataFrame([[1, 2], [3, 4]])
+
+        # should not raise an error
+        df.iloc[np.array(0)]