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

Passing arguments to fsspec backends

Many read/write functions have acquired the storage_options optional argument, to pass a dictionary of parameters to the storage backend. This allows, for example, for passing credentials to S3 and GCS storage. The details of what parameters can be passed to which backends can be found in the documentation of the individual storage backends (detailed from the fsspec docs for builtin implementations and linked to external ones). See Section :ref:`io.remote`.

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

• Bug in :meth:`DataFrame.xs` when used with :class:`IndexSlice` raises TypeError with message Expected label or tuple of labels (:issue:`35301`)

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.count` and :meth:`SeriesGroupBy.sum` returning NaN for missing categories when grouped on multiple Categoricals. Now returning 0 (:issue:`35028`)
• 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

• Bug in :meth:`DataFrame.pivot_table` with aggfunc='count' or aggfunc='sum' returning NaN for missing categories when pivoted on a Categorical. Now returning 0 (:issue:`31422`)

Sparse

ExtensionArray

Other

Contributors