What’s new in 1.2.2 (February 09, 2021)

These are the changes in pandas 1.2.2. See Release notes for a full changelog including other versions of pandas.

Fixed regressions

• Fixed regression in read_excel() that caused it to raise AttributeError when checking version of older xlrd versions (GH38955)

• Fixed regression in DataFrame constructor reordering element when construction from datetime ndarray with dtype not "datetime64[ns]" (GH39422)

• Fixed regression in DataFrame.astype() and Series.astype() not casting to bytes dtype (GH39474)

• Fixed regression in to_pickle() failing to create bz2/xz compressed pickle files with protocol=5 (GH39002)

• Fixed regression in pandas.testing.assert_series_equal() and pandas.testing.assert_frame_equal() always raising AssertionError when comparing extension dtypes (GH39410)

• Fixed regression in to_csv() opening codecs.StreamWriter in binary mode instead of in text mode and ignoring user-provided mode (GH39247)

• Fixed regression in Categorical.astype() casting to incorrect dtype when np.int32 is passed to dtype argument (GH39402)

• Fixed regression in to_excel() creating corrupt files when appending (mode="a") to an existing file (GH39576)

• Fixed regression in DataFrame.transform() failing in case of an empty DataFrame or Series (GH39636)

• Fixed regression in groupby() or resample() when aggregating an all-NaN or numeric object dtype column (GH39329)

• Fixed regression in Rolling.count() where the min_periods argument would be set to 0 after the operation (GH39554)

• Fixed regression in read_excel() that incorrectly raised when the argument io was a non-path and non-buffer and the engine argument was specified (GH39528)

Bug fixes

• pandas.read_excel() error message when a specified sheetname does not exist is now uniform across engines (GH39250)

• Fixed bug in pandas.read_excel() producing incorrect results when the engine openpyxl is used and the excel file is missing or has incorrect dimension information; the fix requires openpyxl >= 3.0.0, prior versions may still fail (GH38956, GH39001)

• Fixed bug in pandas.read_excel() sometimes producing a DataFrame with trailing rows of np.nan when the engine openpyxl is used (GH39181)

Contributors

A total of 14 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

• Andrew Wieteska

• Erfan Nariman

• Joris Van den Bossche

• Matthew Roeschke

• MeeseeksMachine

• Pandas Development Team

• Pav A

• Richard Shadrach

• Simon Hawkins

• Thomas Li

• Torsten Wörtwein

• Vladimir Podolskiy +

• jbrockmendel

• patrick