v1.1.1.rst

What's new in 1.1.1 (August 20, 2020)

These are the changes in pandas 1.1.1. See :ref:`release` for a full changelog including other versions of pandas.

{{ header }}

Fixed regressions

• Fixed regression in :meth:`CategoricalIndex.format` where, when stringified scalars had different lengths, the shorter string would be right-filled with spaces, so it had the same length as the longest string (:issue:`35439`)
• Fixed regression in :meth:`Series.truncate` when trying to truncate a single-element series (:issue:`35544`)
• Fixed regression where :meth:`DataFrame.to_numpy` would raise a RuntimeError for mixed dtypes when converting to str (:issue:`35455`)
• Fixed regression where :func:`read_csv` would raise a ValueError when pandas.options.mode.use_inf_as_na was set to True (:issue:`35493`)
• Fixed regression where :func:`pandas.testing.assert_series_equal` would raise an error when non-numeric dtypes were passed with check_exact=True (:issue:`35446`)
• Fixed regression in .groupby(..).rolling(..) where column selection was ignored (:issue:`35486`)
• Fixed regression where :meth:`DataFrame.interpolate` would raise a TypeError when the :class:`DataFrame` was empty (:issue:`35598`)
• Fixed regression in :meth:`DataFrame.shift` with axis=1 and heterogeneous dtypes (:issue:`35488`)
• Fixed regression in :meth:`DataFrame.diff` with read-only data (:issue:`35559`)
• Fixed regression in .groupby(..).rolling(..) where a segfault would occur with center=True and an odd number of values (:issue:`35552`)
• Fixed regression in :meth:`DataFrame.apply` where functions that altered the input in-place only operated on a single row (:issue:`35462`)
• Fixed regression in :meth:`DataFrame.reset_index` would raise a ValueError on empty :class:`DataFrame` with a :class:`MultiIndex` with a datetime64 dtype level (:issue:`35606`, :issue:`35657`)
• Fixed regression where :func:`pandas.merge_asof` would raise a UnboundLocalError when left_index, right_index and tolerance were set (:issue:`35558`)
• Fixed regression in .groupby(..).rolling(..) where a custom BaseIndexer would be ignored (:issue:`35557`)
• Fixed regression in :meth:`DataFrame.replace` and :meth:`Series.replace` where compiled regular expressions would be ignored during replacement (:issue:`35680`)
• Fixed regression in :meth:`.DataFrameGroupBy.aggregate` where a list of functions would produce the wrong results if at least one of the functions did not aggregate (:issue:`35490`)
• Fixed memory usage issue when instantiating large :class:`pandas.arrays.StringArray` (:issue:`35499`)

Bug fixes

• Bug in :class:`~pandas.io.formats.style.Styler` whereby cell_ids argument had no effect due to other recent changes (:issue:`35588`) (:issue:`35663`)
• Bug in :func:`pandas.testing.assert_series_equal` and :func:`pandas.testing.assert_frame_equal` where extension dtypes were not ignored when check_dtypes was set to False (:issue:`35715`)
• Bug in :meth:`to_timedelta` fails when arg is a :class:`Series` with Int64 dtype containing null values (:issue:`35574`)
• Bug in .groupby(..).rolling(..) where passing closed with column selection would raise a ValueError (:issue:`35549`)
• Bug in :class:`DataFrame` constructor failing to raise ValueError in some cases when data and index have mismatched lengths (:issue:`33437`)

Contributors

.. contributors:: v1.1.0..v1.1.1