CLN: Assorted cleanups (#52318)

Author: rhshadrach

pandas/core/groupby/groupby.py

@@ -2832,18 +2832,17 @@ def blk_func(values: ArrayLike) -> ArrayLike:
             else:
                 # We broadcast algorithms.take_nd analogous to
                 #  np.take_along_axis
-
-                # Note: we only get here with backfill/pad,
-                #  so if we have a dtype that cannot hold NAs,
-                #  then there will be no -1s in indexer, so we can use
-                #  the original dtype (no need to ensure_dtype_can_hold_na)
                 if isinstance(values, np.ndarray):
                     dtype = values.dtype
                     if self.grouper.has_dropped_na:
                         # dropped null groups give rise to nan in the result
                         dtype = ensure_dtype_can_hold_na(values.dtype)
                     out = np.empty(values.shape, dtype=dtype)
                 else:
+                    # Note: we only get here with backfill/pad,
+                    #  so if we have a dtype that cannot hold NAs,
+                    #  then there will be no -1s in indexer, so we can use
+                    #  the original dtype (no need to ensure_dtype_can_hold_na)
                     out = type(values)._empty(values.shape, dtype=values.dtype)
 
                 for i, value_element in enumerate(values):

pandas/tests/groupby/test_api_consistency.py

@@ -4,6 +4,8 @@
 
 import inspect
 
+import pytest
+
 from pandas import (
     DataFrame,
     Series,
@@ -17,8 +19,8 @@
 def test_frame_consistency(groupby_func):
     # GH#48028
     if groupby_func in ("first", "last"):
-        # first and last are entirely different between frame and groupby
-        return
+        msg = "first and last are entirely different between frame and groupby"
+        pytest.skip(reason=msg)
 
     if groupby_func in ("cumcount", "ngroup"):
         assert not hasattr(DataFrame, groupby_func)