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 (GH42355)

  • DataFrame constructed with an older version of pandas could not be unpickled (GH42345)

  • Performance regression in constructing a DataFrame from a dictionary of dictionaries (GH42248)

  • Fixed regression in DataFrame.agg() dropping values when the DataFrame had an Extension Array dtype, a duplicate index, and axis=1 (GH42380)

  • Fixed regression in DataFrame.astype() changing the order of noncontiguous data (GH42396)

  • Performance regression in DataFrame in reduction operations requiring casting such as DataFrame.mean() on integer data (GH38592)

  • Performance regression in DataFrame.to_dict() and Series.to_dict() when orient argument one of “records”, “dict”, or “split” (GH42352)

  • Fixed regression in indexing with a list subclass incorrectly raising TypeError (GH42433, GH42461)

  • Fixed regression in DataFrame.isin() and Series.isin() raising TypeError with nullable data containing at least one missing value (GH42405)

  • Regression in concat() between objects with bool dtype and integer dtype casting to object instead of to integer (GH42092)

  • Bug in Series constructor not accepting a dask.Array (GH38645)

  • Fixed regression for SettingWithCopyWarning displaying incorrect stacklevel (GH42570)

  • Fixed regression for merge_asof() raising KeyError when one of the by columns is in the index (GH34488)

  • Fixed regression in to_datetime() returning pd.NaT for inputs that produce duplicated values, when cache=True (GH42259)

  • Fixed regression in SeriesGroupBy.value_counts() that resulted in an IndexError when called on a Series with one row (GH42618)

Bug fixes

Contributors

For contributors, please see /usr/share/doc/contributors_list.txt or https://github.com/pandas-dev/pandas/graphs/contributors