What’s new in 1.3.1 (July 25, 2021)#

These are the changes in pandas 1.3.1. See Release notes for a full changelog including other versions of pandas.

Fixed regressions#

  • Pandas could not be built on PyPy (GH 42355)

  • DataFrame constructed with an older version of pandas could not be unpickled (GH 42345)

  • Performance regression in constructing a DataFrame from a dictionary of dictionaries (GH 42248)

  • Fixed regression in DataFrame.agg() dropping values when the DataFrame had an Extension Array dtype, a duplicate index, and axis=1 (GH 42380)

  • Fixed regression in DataFrame.astype() changing the order of noncontiguous data (GH 42396)

  • Performance regression in DataFrame in reduction operations requiring casting such as DataFrame.mean() on integer data (GH 38592)

  • Performance regression in DataFrame.to_dict() and Series.to_dict() when orient argument one of “records”, “dict”, or “split” (GH 42352)

  • Fixed regression in indexing with a list subclass incorrectly raising TypeError (GH 42433, GH 42461)

  • Fixed regression in DataFrame.isin() and Series.isin() raising TypeError with nullable data containing at least one missing value (GH 42405)

  • Regression in concat() between objects with bool dtype and integer dtype casting to object instead of to integer (GH 42092)

  • Bug in Series constructor not accepting a dask.Array (GH 38645)

  • Fixed regression for SettingWithCopyWarning displaying incorrect stacklevel (GH 42570)

  • Fixed regression for merge_asof() raising KeyError when one of the by columns is in the index (GH 34488)

  • Fixed regression in to_datetime() returning pd.NaT for inputs that produce duplicated values, when cache=True (GH 42259)

  • Fixed regression in SeriesGroupBy.value_counts() that resulted in an IndexError when called on a Series with one row (GH 42618)

Bug fixes#


A total of 17 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

  • Fangchen Li

  • GYvan +

  • Matthew Roeschke

  • Matthew Zeitlin

  • MeeseeksMachine

  • Pandas Development Team

  • Patrick Hoefler

  • Richard Shadrach

  • Shoham Debnath +

  • Simon Hawkins

  • Stephan Heßelmann +

  • Stephen +

  • Thomas Li

  • Zheyuan +

  • attack68

  • jbrockmendel

  • neelmraman +