Bug in loc raised Error when non-integer slice was given for MultiIndex

doc/source/whatsnew/v1.2.0.rst

@@ -469,6 +469,7 @@ Indexing
 - Bug in :meth:`Index.where` incorrectly casting numeric values to strings (:issue:`37591`)
 - Bug in :meth:`Series.loc` and :meth:`DataFrame.loc` raises when numeric label was given for object :class:`Index` although label was in :class:`Index` (:issue:`26491`)
 - Bug in :meth:`DataFrame.loc` returned requested key plus missing values when ``loc`` was applied to single level from :class:`MultiIndex` (:issue:`27104`)
+- Bug in :meth:`DataFrame.loc` raised ``TypeError`` when non integer interval was given to select values from :class:`MultiIndex` (:issue:`25165`, :issue:`24263`)
 
 Missing
 ^^^^^^^

pandas/core/indexes/multi.py

@@ -2676,10 +2676,15 @@ def _partial_tup_index(self, tup, side="left"):
  return start + section.searchsorted(loc, side=side)
 
  idx = self._get_loc_single_level_index(lev, lab)
- if k < n - 1:
+ if isinstance(idx, slice) and k < n - 1:
+ start = idx.start
+ end = idx.stop
+ elif k < n - 1:
  end = start + section.searchsorted(idx, side="right")
  start = start + section.searchsorted(idx, side="left")
  else:
+ if isinstance(idx, slice):
+ idx = idx.start
  return start + section.searchsorted(idx, side=side)
 
  def _get_loc_single_level_index(self, level_index: Index, key: Hashable) -> int:
@@ -3048,22 +3053,25 @@ def convert_indexer(start, stop, step, indexer=indexer, codes=level_codes):
 
  else:
 
- code = self._get_loc_single_level_index(level_index, key)
+ idx = self._get_loc_single_level_index(level_index, key)
 
  if level > 0 or self.lexsort_depth == 0:
  # Desired level is not sorted
- locs = np.array(level_codes == code, dtype=bool, copy=False)
+ locs = np.array(level_codes == idx, dtype=bool, copy=False)
  if not locs.any():
  # The label is present in self.levels[level] but unused:
  raise KeyError(key)
  return locs
-
- i = level_codes.searchsorted(code, side="left")
- j = level_codes.searchsorted(code, side="right")
- if i == j:
+ if isinstance(idx, slice):
+ start = idx.start
+ end = idx.stop
+ else:
+ start = level_codes.searchsorted(idx, side="left")
+ end = level_codes.searchsorted(idx, side="right")
+ if start == end:
  # The label is present in self.levels[level] but unused:
  raise KeyError(key)
- return slice(i, j)
+ return slice(start, end)
 
  def get_locs(self, seq):
  """

pandas/tests/indexing/multiindex/test_loc.py

@@ -623,3 +623,10 @@ def test_getitem_non_found_tuple():
  )
  with pytest.raises(KeyError, match=r"\(2\.0, 2\.0, 3\.0\)"):
  df.loc[(2.0, 2.0, 3.0)]
+
+
+def test_get_loc_datetime_index():
+ # GH: 18185
+ index = pd.date_range("2001-01-01", periods=100)
+ mi = MultiIndex.from_arrays([index])
+ assert mi.get_loc("2001-01") == slice(0, 31, None)

pandas/tests/indexing/multiindex/test_partial.py

@@ -1,7 +1,14 @@
 import numpy as np
 import pytest
 
-from pandas import DataFrame, Float64Index, Int64Index, MultiIndex
+from pandas import (
+ DataFrame,
+ Float64Index,
+ Int64Index,
+ MultiIndex,
+ date_range,
+ to_datetime,
+)
 import pandas._testing as tm
 
 
@@ -208,6 +215,30 @@ def test_setitem_multiple_partial(self, multiindex_dataframe_random_data):
  expected.loc["bar"] = 0
  tm.assert_series_equal(result, expected)
 
+ def test_partial_getitem_loc_datetime(self):
+ # GH: 25165
+ date_idx = date_range("2019", periods=2, freq="MS")
+ df = DataFrame(
+ list(range(4)),
+ index=MultiIndex.from_product([date_idx, [0, 1]], names=["x", "y"]),
+ )
+ expected = DataFrame(
+ [2, 3],
+ index=MultiIndex.from_product(
+ [[to_datetime("2019-02-01")], [0, 1]], names=["x", "y"]
+ ),
+ )
+ result = df["2019-2":]
+ tm.assert_frame_equal(result, expected)
+ result = df.loc["2019-2":]
+ tm.assert_frame_equal(result, expected)
+
+ result = df.loc(axis=0)["2019-2":]
+ tm.assert_frame_equal(result, expected)
+
+ result = df.loc["2019-2":, :]
+ tm.assert_frame_equal(result, expected)
+
 
 def test_loc_getitem_partial_both_axis():
  # gh-12660