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

pandas/core/indexing.py

@@ -2222,7 +2222,12 @@ def _getitem_axis(self, key, axis=None):
 
         # a single integer
         else:
-            if not is_integer(key):
+            # zero_dim integer np.array is converted to int
+            if isinstance(key, np.ndarray) and key.ndim == 0 \
+                    and issubclass(key.dtype.type, np.integer):
+                key = key.item()
+
+            elif 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)]