v1.2.1.rst

What's new in 1.2.1 (January ??, 2021)

These are the changes in pandas 1.2.1. See :ref:`release` for a full changelog including other versions of pandas.

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Fixed regressions

• The deprecated attributes _AXIS_NAMES and _AXIS_NUMBERS of :class:`DataFrame` and :class:`Series` will no longer show up in dir or inspect.getmembers calls (:issue:`38740`)
• Fixed regression in :meth:`to_csv` that created corrupted zip files when there were more rows than chunksize (:issue:`38714`)
• Fixed a regression in groupby().rolling() where :class:`MultiIndex` levels were dropped (:issue:`38523`)
• Fixed regression in repr of float-like strings of an object dtype having trailing 0's truncated after the decimal (:issue:`38708`)
• Fixed regression in :meth:`DataFrame.groupby()` with :class:`Categorical` grouping column not showing unused categories for grouped.indices (:issue:`38642`)
• Fixed regression in :meth:`DataFrame.any` and :meth:`DataFrame.all` not returning a result for tz-aware datetime64 columns (:issue:`38723`)
• Fixed regression in :meth:`DataFrame.__setitem__` raising ValueError when expanding :class:`DataFrame` and new column is from type "0 - name" (:issue:`39010`)
• Fixed regression in :meth:`.GroupBy.sem` where the presence of non-numeric columns would cause an error instead of being dropped (:issue:`38774`)
• Fixed regression in :meth:`DataFrame.loc.__setitem__` raising ValueError when :class:`DataFrame` has unsorted :class:`MultiIndex` columns and indexer is a scalar (:issue:`38601`)
• Fixed regression in :func:`read_excel` with non-rawbyte file handles (:issue:`38788`)
• Bug in :meth:`read_csv` with float_precision="high" caused segfault or wrong parsing of long exponent strings. This resulted in a regression in some cases as the default for float_precision was changed in pandas 1.2.0 (:issue:`38753`)
• Fixed regression in :meth:`DataFrameGroupBy.diff` raising for int8 and int16 columns (:issue:`39050`)
• Fixed regression in :meth:`Rolling.skew` and :meth:`Rolling.kurt` modifying the object inplace (:issue:`38908`)
• Fixed regression in :meth:`read_csv` and other read functions were the encoding error policy (errors) did not default to "replace" when no encoding was specified (:issue:`38989`)
• Fixed regression in :meth:`DataFrame.replace` raising ValueError when :class:`DataFrame` has dtype bytes (:issue:`38900`)

Bug fixes

I/O

• Bumped minimum fastparquet version to 0.4.0 to avoid AttributeError from numba (:issue:`38344`)
• Bumped minimum pymysql version to 0.8.1 to avoid test failures (:issue:`38344`)
• Fixed AttributeError with PyArrow versions [0.16.0, 1.0.0) (:issue:`38801`)

Other

• Fixed build failure on MacOS 11 in Python 3.9.1 (:issue:`38766`)
• Added reference to backwards incompatible check_freq arg of :func:`testing.assert_frame_equal` and :func:`testing.assert_series_equal` in :ref:`pandas 1.1.0 whats new <whatsnew_110.api_breaking.testing.check_freq>` (:issue:`34050`)

Contributors

.. contributors:: v1.2.0..v1.2.1|HEAD