What’s new in 2.1.2 (October 26, 2023)#

These are the changes in pandas 2.1.2. See Release notes for a full changelog including other versions of pandas.


Fixed regressions#

  • Fixed regression in DataFrame.join() where result has missing values and dtype is arrow backed string (GH 55348)

  • Fixed regression in rolling() where non-nanosecond index or on column would produce incorrect results (GH 55026, GH 55106, GH 55299)

  • Fixed regression in DataFrame.resample() which was extrapolating back to origin when origin was outside its bounds (GH 55064)

  • Fixed regression in DataFrame.sort_index() which was not sorting correctly when the index was a sliced MultiIndex (GH 55379)

  • Fixed regression in DataFrameGroupBy.agg() and SeriesGroupBy.agg() where if the option compute.use_numba was set to True, groupby methods not supported by the numba engine would raise a TypeError (GH 55520)

  • Fixed performance regression with wide DataFrames, typically involving methods where all columns were accessed individually (GH 55256, GH 55245)

  • Fixed regression in merge_asof() raising TypeError for by with datetime and timedelta dtypes (GH 55453)

  • Fixed regression in read_parquet() when reading a file with a string column consisting of more than 2 GB of string data and using the "string" dtype (GH 55606)

  • Fixed regression in DataFrame.to_sql() not roundtripping datetime columns correctly for sqlite when using detect_types (GH 55554)

  • Fixed regression in construction of certain DataFrame or Series subclasses (GH 54922)

Bug fixes#


  • Fixed non-working installation of optional dependency group output_formatting. Replacing underscore _ with a dash - fixes broken dependency resolution. A correct way to use now is pip install pandas[output-formatting].


A total of 20 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

  • Amanda Bizzinotto

  • Artur Barseghyan +

  • Hadi Abdi Khojasteh +

  • Joris Van den Bossche

  • Luke Manley

  • Lumberbot (aka Jack)

  • Marc Garcia

  • Marco Edward Gorelli

  • MarcoGorelli

  • Mateusz Sokół

  • Matthew Roeschke

  • Natalia Mokeeva

  • Pandas Development Team

  • Patrick Hoefler

  • Richard Shadrach

  • Thomas Li

  • Yao Xiao

  • dependabot[bot]

  • rohanjain101 +

  • torext +