add test for frequency of DatetimeIndex in MultiIndex

Author: [Annika Rudolph]

pandas/core/arrays/datetimelike.py

@@ -20,7 +20,6 @@
 
 import numpy as np
 
-from pandas.core.algorithms import take
 from pandas._config.config import get_option
 
 from pandas._libs import (
@@ -67,9 +66,9 @@
     ScalarIndexer,
     Self,
     SequenceIndexer,
+    TakeIndexer,
     TimeAmbiguous,
     TimeNonexistent,
-    TakeIndexer,
     npt,
 )
 from pandas.compat.numpy import function as nv
@@ -119,6 +118,7 @@
 from pandas.core.algorithms import (
     isin,
     map_array,
+    take,
     unique1d,
 )
 from pandas.core.array_algos import datetimelike_accumulations
@@ -2386,6 +2386,7 @@ def take(
             axis=axis,
         )    
         result = self._from_backing_data(new_data)
+        
         indices = np.asarray(indices, dtype=np.intp)
         maybe_slice = lib.maybe_indices_to_slice(indices, len(self))
 

pandas/tests/indexes/multi/test_get_level_values.py

@@ -122,3 +122,14 @@ def test_values_loses_freq_of_underlying_index():
     midx.values
     assert idx.freq is not None
     tm.assert_index_equal(idx, expected)
+
+
+def test_get_level_values_gets_frequency_correctly():
+    # GH#57949 GH#58327
+    datetime_index = pd.date_range(start=pd.to_datetime("1/1/2018"), 
+                                   periods = 4, 
+                                   freq = 'YS')
+    other_index = ["A"]
+    multi_index = pd.MultiIndex.from_product([datetime_index, other_index])
+
+    assert  multi_index.get_level_values(0).freq is datetime_index.freq