Reverted downstream changes, new error message

doc/source/whatsnew/v1.1.2.rst

@@ -23,6 +23,7 @@ Fixed regressions
 - Fixed regression in :meth:`DataFrameGroupBy.agg` where a ``ValueError: buffer source array is read-only`` would be raised when the underlying array is read-only (:issue:`36014`)
 - Fixed regression in :meth:`Series.__getitem__` incorrectly raising when the input was a tuple. (:issue:`35534`)
 - Fixed regression in :meth:`Series.__getitem__` incorrectly raising when the input was a frozenset. (:issue:`35747`)
+-
 
 .. ---------------------------------------------------------------------------
 

pandas/core/series.py

@@ -922,7 +922,7 @@ def _get_with(self, key):
  "Indexing a Series with DataFrame is not "
  "supported, use the appropriate DataFrame column"
  )
- elif isinstance(key, tuple) and isinstance(self.index, MultiIndex):
+ elif isinstance(key, tuple):
  return self._get_values_tuple(key)
 
  elif not is_list_like(key):
@@ -958,7 +958,7 @@ def _get_values_tuple(self, key):
  return result
 
  if not isinstance(self.index, MultiIndex):
- raise ValueError("Can only tuple-index with a MultiIndex")
+ raise ValueError("key of type tuple not found and not a MultiIndex")
 
  # If key is contained, would have returned by now
  indexer, new_index = self.index.get_loc_level(key)
@@ -1014,7 +1014,9 @@ def __setitem__(self, key, value):
 
  except TypeError as e:
  if isinstance(key, tuple) and not isinstance(self.index, MultiIndex):
- raise ValueError("Can only tuple-index with a MultiIndex") from e
+ raise ValueError(
+ "key of type tuple not found and not a MultiIndex"
+ ) from e
 
  if com.is_bool_indexer(key):
  key = check_bool_indexer(self.index, key)

pandas/tests/series/indexing/test_indexing.py

@@ -383,7 +383,7 @@ def test_2d_to_1d_assignment_raises():
 @pytest.mark.filterwarnings("ignore:Using a non-tuple:FutureWarning")
 def test_basic_getitem_setitem_corner(datetime_series):
  # invalid tuples, e.g. td.ts[:, None] vs. td.ts[:, 2]
- msg = "Can only tuple-index with a MultiIndex"
+ msg = "key of type tuple not found and not a MultiIndex"
  with pytest.raises(ValueError, match=msg):
  datetime_series[:, 2]
  with pytest.raises(ValueError, match=msg):