Skip test related to GH 18111, lint

Author: mroeschke

doc/source/whatsnew/v0.21.0.txt

@@ -999,7 +999,6 @@ Performance Improvements
 - :attr:`Timestamp.microsecond` no longer re-computes on attribute access (:issue:`17331`)
 - Improved performance of the :class:`CategoricalIndex` for data that is already categorical dtype (:issue:`17513`)
 - Improved performance of :meth:`RangeIndex.min` and :meth:`RangeIndex.max` by using ``RangeIndex`` properties to perform the computations (:issue:`17607`)
-- Added a keyword argument, `cache`, to :func:`to_datetime` that improved the performance of converting duplicate datetime arguments (:issue: `11665`)
 
 .. _whatsnew_0210.docs:
 

doc/source/whatsnew/v0.21.1.txt

@@ -39,7 +39,7 @@ Deprecations
 Performance Improvements
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
--
+- Added a keyword argument, `cache`, to :func:`to_datetime` that improved the performance of converting duplicate datetime arguments (:issue: `11665`)
 -
 -
 

pandas/core/tools/datetimes.py

@@ -35,6 +35,7 @@ def _guess_datetime_format_for_array(arr, **kwargs):
     if len(non_nan_elements):
         return _guess_datetime_format(arr[non_nan_elements[0]], **kwargs)
 
+
 def _maybe_cache(arg, format, cache, tz, _convert_listlike):
     """Create a cache of unique dates from an array of dates"""
     from pandas import Series
@@ -49,6 +50,7 @@ def _maybe_cache(arg, format, cache, tz, _convert_listlike):
             cache_array = Series(cache_dates, index=unique_dates)
     return cache_array
 
+
 def _convert_and_box_cache(arg, cache_array, box, errors, tz, name=None):
     """Convert array of dates with a cache and box the result"""
     from pandas import Series
@@ -62,6 +64,7 @@ def _convert_and_box_cache(arg, cache_array, box, errors, tz, name=None):
             result = DatetimeIndex(result, tz=tz, name=name)
     return result
 
+
 def to_datetime(arg, errors='raise', dayfirst=False, yearfirst=False,
                 utc=None, box=True, format=None, exact=True,
                 unit=None, infer_datetime_format=False, origin='unix',
@@ -138,11 +141,11 @@ def to_datetime(arg, errors='raise', dayfirst=False, yearfirst=False,
           origin.
 
         .. versionadded: 0.20.0
-    cache : boolean, default True
-        If True, use a cache of unique, converted dates to apply the datetime
+    cache : boolean, default False
+        If False, use a cache of unique, converted dates to apply the datetime
         conversion. Produces signficant speed-ups when parsing duplicate dates.
 
-        .. versionadded: 0.21.0
+        .. versionadded: 0.21.1
     Returns
     -------
     ret : datetime if parsing succeeded.

pandas/tests/indexes/datetimes/test_tools.py

@@ -372,7 +372,10 @@ def test_to_datetime_tz_psycopg2(self, cache):
                                     dtype='datetime64[ns, UTC]')
         tm.assert_index_equal(result, expected)
 
-    @pytest.mark.parametrize('cache', [True, False])
+    bool_skip = pytest.mark.skipif(True, reason="GH 18111")
+
+    @pytest.mark.parametrize('cache', [pytest.param(True, marks=bool_skip),
+                                       False])
     def test_datetime_bool(self, cache):
         # GH13176
         with pytest.raises(TypeError):
@@ -450,7 +453,6 @@ def test_week_without_day_and_calendar_year(self, date, format):
 
 
 class TestToDatetimeUnit(object):
-
     @pytest.mark.parametrize('cache', [True, False])
     def test_unit(self, cache):
         # GH 11758