What's new in 1.0.1 (??)

These are the changes in pandas 1.0.1. See :ref:`release` for a full changelog including other versions of pandas.

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Deprecations

Support for negative integer for :attr:`pd.options.display.max_colwidth` is deprecated in favor of using None (:issue:`31532`)

Bug fixes

Bug in :meth:`GroupBy.apply` was raising TypeError if called with function which returned a non-pandas non-scalar object (e.g. a list) (:issue:`31441`)

Categorical

Datetimelike

Fixed regression in :meth:`to_datetime` when parsing non-nanosecond resolution datetimes (:issue:`31491`)
Fixed bug in :meth:`to_datetime` raising when cache=True and out-of-bound values are present (:issue:`31491`)

Timedelta

Timezones

Numeric

Bug in dtypes being lost in DataFrame.__invert__ (~ operator) with mixed dtypes (:issue:`31183`)
Bug in :class:`Series` multiplication when multiplying a numeric :class:`Series` with >10000 elements with a timedelta-like scalar (:issue:`31467`)

Conversion

Strings

Interval

Indexing

Fixed regression when indexing a Series or DataFrame indexed by DatetimeIndex with a slice containg a :class:`datetime.date` (:issue:`31501`)
Fixed regression in :class:`DataFrame` setting values with a slice (e.g. df[-4:] = 1) indexing by label instead of position (:issue:`31469`)
Bug where assigning to a :class:`Series` using a IntegerArray / BooleanArray as a mask would raise TypeError (:issue:`31446`)

Missing

MultiIndex

I/O

Fixed regression in :meth:`~DataFrame.to_csv` where specifying an na_rep might truncate the values written (:issue:`31447`)

Plotting

Groupby/resample/rolling

Bug in :meth:`DataFrame.groupby` whereby taking the minimum or maximum of a column with period dtype would raise a TypeError. (:issue:`31471`)

Reshaping

Sparse

ExtensionArray

Bug in dtype being lost in __invert__ (~ operator) for extension-array backed Series and DataFrame (:issue:`23087`)

Other

Regression fixed in objTOJSON.c fix return-type warning (:issue:`31463`)
Fixed a regression where setting :attr:`pd.options.display.max_colwidth` was not accepting negative integer. In addition, this behavior has been deprecated in favor of using None (:issue:`31532`)

Contributors