What’s new in 1.1.4 (October 30, 2020)

These are the changes in pandas 1.1.4. See Release notes for a full changelog including other versions of pandas.

Fixed regressions

• Fixed regression in read_csv() raising a ValueError when names was of type dict_keys (GH36928)

• Fixed regression in read_csv() with more than 1M rows and specifying a index_col argument (GH37094)

• Fixed regression where attempting to mutate a DateOffset object would no longer raise an AttributeError (GH36940)

• Fixed regression where DataFrame.agg() would fail with TypeError when passed positional arguments to be passed on to the aggregation function (GH36948).

• Fixed regression in RollingGroupby with sort=False not being respected (GH36889)

• Fixed regression in Series.astype() converting None to "nan" when casting to string (GH36904)

• Fixed regression in Series.rank() method failing for read-only data (GH37290)

• Fixed regression in RollingGroupby causing a segmentation fault with Index of dtype object (GH36727)

• Fixed regression in DataFrame.resample(...).apply(...)() raised AttributeError when input was a DataFrame and only a Series was evaluated (GH36951)

• Fixed regression in DataFrame.groupby(..).std() with nullable integer dtype (GH37415)

• Fixed regression in PeriodDtype comparing both equal and unequal to its string representation (GH37265)

• Fixed regression where slicing DatetimeIndex raised AssertionError on irregular time series with pd.NaT or on unsorted indices (GH36953 and GH35509)

• Fixed regression in certain offsets (pd.offsets.Day() and below) no longer being hashable (GH37267)

• Fixed regression in StataReader which required chunksize to be manually set when using an iterator to read a dataset (GH37280)

• Fixed regression in setitem with DataFrame.iloc() which raised error when trying to set a value while filtering with a boolean list (GH36741)

• Fixed regression in setitem with a Series getting aligned before setting the values (GH37427)

• Fixed regression in MultiIndex.is_monotonic_increasing returning wrong results with NaN in at least one of the levels (GH37220)

• Fixed regression in inplace arithmetic operation (+=) on a Series not updating the parent DataFrame/Series (GH36373)

Bug fixes

• Bug causing groupby(...).sum() and similar to not preserve metadata (GH29442)

• Bug in Series.isin() and DataFrame.isin() raising a ValueError when the target was read-only (GH37174)

• Bug in DataFrameGroupBy.fillna() and SeriesGroupBy.fillna() that introduced a performance regression after 1.0.5 (GH36757)

• Bug in DataFrame.info() was raising a KeyError when the DataFrame has integer column names (GH37245)

• Bug in DataFrameGroupby.apply() would drop a CategoricalIndex when grouped on (GH35792)

Contributors

A total of 18 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

• Daniel Saxton

• Fangchen Li

• Janus +

• Joris Van den Bossche

• Kevin Sheppard

• Marco Gorelli

• Matt Roeschke

• Matthew Roeschke

• MeeseeksMachine

• Pandas Development Team

• Paul Ganssle

• Richard Shadrach

• Simon Hawkins

• Thomas Smith

• Tobias Pitters

• abmyii +

• jbrockmendel

• patrick