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# 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` (GH 36928)

- Fixed regression in `read_csv()` with more than 1M rows and specifying a `index_col` argument (GH 37094)

- Fixed regression where attempting to mutate a `DateOffset` object would no longer raise an `AttributeError` (GH 36940)

- Fixed regression where `DataFrame.agg()` would fail with `TypeError` when passed positional arguments to be passed on to the aggregation function (GH 36948).

- Fixed regression in `RollingGroupby` with `sort=False` not being respected (GH 36889)

- Fixed regression in `Series.astype()` converting `None` to `"nan"` when casting to string (GH 36904)

- Fixed regression in `Series.rank()` method failing for read-only data (GH 37290)

- Fixed regression in `RollingGroupby` causing a segmentation fault with Index of dtype object (GH 36727)

- Fixed regression in `DataFrame.resample(...).apply(...)()` raised `AttributeError` when input was a `DataFrame` and only a `Series` was evaluated (GH 36951)

- Fixed regression in `DataFrame.groupby(..).std()` with nullable integer dtype (GH 37415)

- Fixed regression in `PeriodDtype` comparing both equal and unequal to its string representation (GH 37265)

- Fixed regression where slicing `DatetimeIndex` raised `AssertionError` on irregular time series with `pd.NaT` or on unsorted indices (GH 36953 and GH 35509)

- Fixed regression in certain offsets (`pd.offsets.Day()` and below) no longer being hashable (GH 37267)

- Fixed regression in `StataReader` which required `chunksize` to be manually set when using an iterator to read a dataset (GH 37280)

- Fixed regression in setitem with `DataFrame.iloc()` which raised error when trying to set a value while filtering with a boolean list (GH 36741)

- Fixed regression in setitem with a Series getting aligned before setting the values (GH 37427)

- Fixed regression in `MultiIndex.is_monotonic_increasing` returning wrong results with `NaN` in at least one of the levels (GH 37220)

- Fixed regression in inplace arithmetic operation (+=) on a Series not updating the parent DataFrame/Series (GH 36373)

## Bug fixes

- Bug causing `groupby(...).sum()` and similar to not preserve metadata (GH 29442)

- Bug in `Series.isin()` and `DataFrame.isin()` raising a `ValueError` when the target was read-only (GH 37174)

- Bug in `DataFrameGroupBy.fillna()` and `SeriesGroupBy.fillna()` that introduced a performance regression after 1.0.5 (GH 36757)

- Bug in `DataFrame.info()` was raising a `KeyError` when the DataFrame has integer column names (GH 37245)

- Bug in `DataFrameGroupby.apply()` would drop a `CategoricalIndex` when grouped on (GH 35792)

## 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