Undo formatting

Author: mroeschke

doc/source/whatsnew/v0.21.0.txt

@@ -405,6 +405,7 @@ Conversion
 - Bug in ``IntervalIndex.is_non_overlapping_monotonic`` when intervals are closed on both sides and overlap at a point (:issue:`16560`)
 - Bug in :func:`Series.fillna` returns frame when ``inplace=True`` and ``value`` is dict (:issue:`16156`)
 
+
 Indexing
 ^^^^^^^^
 

pandas/core/tools/datetimes.py

@@ -365,7 +365,6 @@ def _convert_listlike(arg, box, format, name=None, tz=tz):
                 except ValueError:
                     pass
 
-
             return arg
 
         elif unit is not None:
@@ -385,13 +384,11 @@ def _convert_listlike(arg, box, format, name=None, tz=tz):
             raise TypeError('arg must be a string, datetime, list, tuple, '
                             '1-d array, or Series')
 
-
         arg = _ensure_object(arg)
         require_iso8601 = False
 
         if infer_datetime_format and format is None:
-            format = _guess_datetime_format_for_array(arg,
-                                                      dayfirst=dayfirst)
+            format = _guess_datetime_format_for_array(arg, dayfirst=dayfirst)
 
         if format is not None:
             # There is a special fast-path for iso8601 formatted
@@ -418,8 +415,7 @@ def _convert_listlike(arg, box, format, name=None, tz=tz):
                 # fallback
                 if result is None:
                     try:
-                        result = tslib.array_strptime(arg, format,
-                                                      exact=exact,
+                        result = tslib.array_strptime(arg, format, exact=exact,
                                                       errors=errors)
                     except tslib.OutOfBoundsDatetime:
                         if errors == 'raise':
@@ -443,6 +439,7 @@ def _convert_listlike(arg, box, format, name=None, tz=tz):
                     yearfirst=yearfirst,
                     require_iso8601=require_iso8601
                 )
+
             if is_datetime64_dtype(result) and box:
                 result = DatetimeIndex(result, tz=tz, name=name)
             return result

pandas/io/sql.py

@@ -821,7 +821,7 @@ def _harmonize_columns(self, parse_dates=None):
                 if (col_type is datetime or col_type is date or
                         col_type is DatetimeTZDtype):
                     if col_type is DatetimeTZDtype:
-                        # Convert SQL Datetime columns with tz to UTC
+                        # Convert tz-aware Datetime SQL columns to UTC
                         self.frame[col_name] = _handle_date_column(df_col, 
                                                                    utc=True)
                     else: