v1.2.0.rst

What's new in 1.2.0 (??)

These are the changes in pandas 1.2.0. See :ref:`release` for a full changelog including other versions of pandas.

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Enhancements

Support for binary file handles in to_csv

:meth:`to_csv` supports file handles in binary mode (:issue:`19827` and :issue:`35058`) with encoding (:issue:`13068` and :issue:`23854`) and compression (:issue:`22555`). mode has to contain a b for binary handles to be supported.

For example:

.. ipython:: python

   import io

   data = pd.DataFrame([0, 1, 2])
   buffer = io.BytesIO()
   data.to_csv(buffer, mode="w+b", encoding="utf-8", compression="gzip")

Other enhancements

• :class:`Index` with object dtype supports division and multiplication (:issue:`34160`)

Deprecations

Performance improvements

Bug fixes

Categorical

Datetimelike

• Bug in :attr:`DatetimeArray.date` where a ValueError would be raised with a read-only backing array (:issue:`33530`)
• Bug in NaT comparisons failing to raise TypeError on invalid inequality comparisons (:issue:`35046`)

Timedelta

• Bug in :class:`TimedeltaIndex`, :class:`Series`, and :class:`DataFrame` floor-division with timedelta64 dtypes and NaT in the denominator (:issue:`35529`)

Timezones

• Bug in :func:`date_range` was raising AmbiguousTimeError for valid input with ambiguous=False (:issue:`35297`)

Numeric

Conversion

Strings

Interval

Indexing

Missing

MultiIndex

I/O

• Bug in :meth:`to_csv` caused a ValueError when it was called with a filename in combination with mode containing a b (:issue:`35058`)

Plotting

Groupby/resample/rolling

• Bug in :meth:`DataFrameGroupBy.apply` that would some times throw an erroneous ValueError if the grouping axis had duplicate entries (:issue:`16646`)
• Bug in :meth:`DataFrameGroupBy.apply` where a non-nuisance grouping column would be dropped from the output columns if another groupby method was called before .apply() (:issue:`34656`)

Reshaping

Sparse

ExtensionArray

Other

Contributors