Merge branch 'master' into PR21194

doc/source/whatsnew/v0.23.1.txt

@@ -93,11 +93,7 @@ Performance Improvements
 Bug Fixes
 ~~~~~~~~~
 
-- Bug in :func:`Dataframe.asof` that raised a ``TypeError`` when attempting to compare tz-naive and tz-aware timestamps (:issue:`21194`)
-
-
-Groupby/Resample/Rolling
-^^^^^^^^^^^^^^^^^^^^^^^^
+**Groupby/Resample/Rolling**
 
 - Bug in :func:`DataFrame.agg` where applying multiple aggregation functions to a :class:`DataFrame` with duplicated column names would cause a stack overflow (:issue:`21063`)
 - Bug in :func:`pandas.core.groupby.GroupBy.ffill` and :func:`pandas.core.groupby.GroupBy.bfill` where the fill within a grouping would not always be applied as intended due to the implementations' use of a non-stable sort (:issue:`21207`)
@@ -114,14 +110,7 @@ Groupby/Resample/Rolling
 
 - Bug in :attr:`SparseArray.shape` which previously only returned the shape :attr:`SparseArray.sp_values` (:issue:`21126`)
 
-Conversion
-^^^^^^^^^^
-
-- Bug in :func:`Dataframe.asof` that raised a ``TypeError`` when attempting to compare tz-naive and tz-aware timestamps (:issue:`21194`)
--
-
-Indexing
-^^^^^^^^
+**Indexing**
 
 - Bug in :meth:`Series.reset_index` where appropriate error was not raised with an invalid level name (:issue:`20925`)
 - Bug in :func:`interval_range` when ``start``/``periods`` or ``end``/``periods`` are specified with float ``start`` or ``end`` (:issue:`21161`)
@@ -148,5 +137,4 @@ Indexing
 **Other**
 
 - Tab completion on :class:`Index` in IPython no longer outputs deprecation warnings (:issue:`21125`)
-- Bug preventing pandas from being importable with -OO optimization (:issue:`21071`)
-
+- Bug preventing pandas being used on Windows without C++ redistributable installed (:issue:`21106`)

pandas/io/excel.py

@@ -530,9 +530,8 @@ def _parse_excel(self,
  "is not implemented")
 
  if parse_dates is True and index_col is None:
-
- warn("The 'parse_dates=True' keyword of read_excel was provided"
- " without an 'index_col' keyword value.")
+ warnings.warn("The 'parse_dates=True' keyword of read_excel was "
+ "provided without an 'index_col' keyword value.")
 
  import xlrd
  from xlrd import (xldate, XL_CELL_DATE,