REF: simplify is_scalar_indexer (#44234)

Author: jbrockmendel

pandas/core/indexers/utils.py

@@ -100,10 +100,7 @@ def is_scalar_indexer(indexer, ndim: int) -> bool:
         # GH37748: allow indexer to be an integer for Series
         return True
     if isinstance(indexer, tuple) and len(indexer) == ndim:
-        return all(
-            is_integer(x) or (isinstance(x, np.ndarray) and x.ndim == len(x) == 1)
-            for x in indexer
-        )
+        return all(is_integer(x) for x in indexer)
     return False
 
 

pandas/tests/indexing/test_indexers.py

@@ -22,10 +22,10 @@ def test_is_scalar_indexer():
     assert not is_scalar_indexer(indexer[0], 2)
 
     indexer = (np.array([2]), 1)
-    assert is_scalar_indexer(indexer, 2)
+    assert not is_scalar_indexer(indexer, 2)
 
     indexer = (np.array([2]), np.array([3]))
-    assert is_scalar_indexer(indexer, 2)
+    assert not is_scalar_indexer(indexer, 2)
 
     indexer = (np.array([2]), np.array([3, 4]))
     assert not is_scalar_indexer(indexer, 2)