doc/source/whatsnew/v2.2.1.rst
.. _whatsnew_221:
These are the changes in pandas 2.2.1. See :ref:release for a full changelog
including other versions of pandas.
{{ header }}
.. --------------------------------------------------------------------------- .. _whatsnew_221.enhancements:
Enhancements
- Added ``pyarrow`` pip extra so users can install pandas and pyarrow with pip with ``pip install pandas[pyarrow]`` (:issue:`54466`)
.. _whatsnew_221.regressions:
Fixed regressions
read_csv (:issue:57039)Series.combine_first (:issue:55845)57150)concat changing long-standing behavior that always sorted the non-concatenation axis when the axis was a :class:DatetimeIndex (:issue:57006)merge_ordered raising TypeError for fill_method="ffill" and how="left" (:issue:57010)pandas.testing.assert_series_equal defaulting to check_exact=True when checking the :class:Index (:issue:57067)read_json where an :class:Index would be returned instead of a :class:RangeIndex (:issue:57429)wide_to_long raising an AttributeError for string columns (:issue:57066).DataFrameGroupBy.idxmin, :meth:.DataFrameGroupBy.idxmax, :meth:.SeriesGroupBy.idxmin, :meth:.SeriesGroupBy.idxmax ignoring the skipna argument (:issue:57040).DataFrameGroupBy.idxmin, :meth:.DataFrameGroupBy.idxmax, :meth:.SeriesGroupBy.idxmin, :meth:.SeriesGroupBy.idxmax where values containing the minimum or maximum value for the dtype could produce incorrect results (:issue:57040)CategoricalIndex.difference raising KeyError when other contains null values other than NaN (:issue:57318)DataFrame.groupby raising ValueError when grouping by a :class:Series in some cases (:issue:57276)DataFrame.loc raising IndexError for non-unique, masked dtype indexes where result has more than 10,000 rows (:issue:57027)DataFrame.loc which was unnecessarily throwing "incompatible dtype warning" when expanding with partial row indexer and multiple columns (see PDEP6 <https://pandas.pydata.org/pdeps/0006-ban-upcasting.html>_) (:issue:56503)DataFrame.map with na_action="ignore" not being respected for NumPy nullable and :class:ArrowDtypes (:issue:57316)DataFrame.merge raising ValueError for certain types of 3rd-party extension arrays (:issue:57316)DataFrame.query with all NaT column with object dtype (:issue:57068)DataFrame.shift raising AssertionError for axis=1 and empty :class:DataFrame (:issue:57301)DataFrame.sort_index not producing a stable sort for a index with duplicates (:issue:57151)DataFrame.to_dict with orient='list' and datetime or timedelta types returning integers (:issue:54824)DataFrame.to_json converting nullable integers to floats (:issue:57224)DataFrame.to_sql when method="multi" is passed and the dialect type is not Oracle (:issue:57310)DataFrame.transpose with nullable extension dtypes not having F-contiguous data potentially causing exceptions when used (:issue:57315)DataFrame.update emitting incorrect warnings about downcasting (:issue:57124)DataFrameGroupBy.idxmin, :meth:DataFrameGroupBy.idxmax, :meth:SeriesGroupBy.idxmin, :meth:SeriesGroupBy.idxmax ignoring the skipna argument (:issue:57040)DataFrameGroupBy.idxmin, :meth:DataFrameGroupBy.idxmax, :meth:SeriesGroupBy.idxmin, :meth:SeriesGroupBy.idxmax where values containing the minimum or maximum value for the dtype could produce incorrect results (:issue:57040)ExtensionArray.to_numpy raising for non-numeric masked dtypes (:issue:56991)Index.join raising TypeError when joining an empty index to a non-empty index containing mixed dtype values (:issue:57048)Series.astype introducing decimals when converting from integer with missing values to string dtype (:issue:57418)Series.pct_change raising a ValueError for an empty :class:Series (:issue:57056)Series.to_numpy when dtype is given as float and the data contains NaNs (:issue:57121)DateOffset objects with millisecond components to datetime64 :class:Index, :class:Series, or :class:DataFrame (:issue:57529).. --------------------------------------------------------------------------- .. _whatsnew_221.bug_fixes:
Bug fixes
- Fixed bug in :func:`pandas.api.interchange.from_dataframe` which was raising for Nullable integers (:issue:`55069`)
- Fixed bug in :func:`pandas.api.interchange.from_dataframe` which was raising for empty inputs (:issue:`56700`)
- Fixed bug in :func:`pandas.api.interchange.from_dataframe` which wasn't converting columns names to strings (:issue:`55069`)
- Fixed bug in :meth:`DataFrame.__getitem__` for empty :class:`DataFrame` with Copy-on-Write enabled (:issue:`57130`)
- Fixed bug in :meth:`PeriodIndex.asfreq` which was silently converting frequencies which are not supported as period frequencies instead of raising an error (:issue:`56945`)
.. ---------------------------------------------------------------------------
.. _whatsnew_221.other:
Other
~~~~~
.. note::
The ``DeprecationWarning`` that was raised when pandas was imported without PyArrow being
installed has been removed. This decision was made because the warning was too noisy for too
many users and a lot of feedback was collected about the decision to make PyArrow a required
dependency. Pandas is currently considering the decision whether or not PyArrow should be added
as a hard dependency in 3.0. Interested users can follow the discussion
`here <https://github.com/pandas-dev/pandas/issues/57073>`_.
- Added the argument ``skipna`` to :meth:`DataFrameGroupBy.first`, :meth:`DataFrameGroupBy.last`, :meth:`SeriesGroupBy.first`, and :meth:`SeriesGroupBy.last`; achieving ``skipna=False`` used to be available via :meth:`DataFrameGroupBy.nth`, but the behavior was changed in pandas 2.0.0 (:issue:`57019`)
- Added the argument ``skipna`` to :meth:`Resampler.first`, :meth:`Resampler.last` (:issue:`57019`)
.. ---------------------------------------------------------------------------
.. _whatsnew_221.contributors:
Contributors
.. contributors:: v2.2.0..v2.2.1