v0.24.1.rst

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Whats New in 0.24.1 (February XX, 2019)

Warning

The 0.24.x series of releases will be the last to support Python 2. Future feature releases will support Python 3 only. See :ref:`install.dropping-27` for more.

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These are the changes in pandas 0.24.1. See :ref:`release` for a full changelog including other versions of pandas.

API Changes

Changing the sort parameter for :meth:`Index.union`

The default sort value for :meth:`Index.union` has changed from True to None (:issue:`24959`). The default behavior remains the same: The result is sorted, unless

1. self and other are identical
2. self or other is empty
3. self or other contain values that can not be compared (a RuntimeWarning is raised).

This allows sort=True to now mean "always sort". A TypeError is raised if the values cannot be compared.

Behavior in 0.24.0

.. ipython:: python

   In [1]: idx = pd.Index(['b', 'a'])

   In [2]: idx.union(idx)  # sort=True was the default.
   Out[2]: Index(['b', 'a'], dtype='object')

   In [3]: idx.union(idx, sort=True)  # result is still not sorted.
   Out[32]: Index(['b', 'a'], dtype='object')

New Behavior

.. ipython:: python

   idx = pd.Index(['b', 'a'])
   idx.union(idx)  # sort=None is the default. Don't sort identical operands.

   idx.union(idx, sort=True)

The same change applies to :meth:`Index.difference` and :meth:`Index.symmetric_difference`, which would previously not sort the result when sort=True but the values could not be compared.

Changed the behavior of :meth:`Index.intersection` with sort=True

When sort=True is provided to :meth:`Index.intersection`, the values are always sorted. In 0.24.0, the values would not be sorted when self and other were identical. Pass sort=False to not sort the values. This matches the behavior of pandas 0.23.4 and earlier.

Behavior in 0.23.4

.. ipython:: python

   In [2]: idx = pd.Index(['b', 'a'])

   In [3]: idx.intersection(idx)  # sort was not a keyword.
   Out[3]: Index(['b', 'a'], dtype='object')

Behavior in 0.24.0

.. ipython:: python

   In [5]: idx.intersection(idx)  # sort=True by default. Don't sort identical.
   Out[5]: Index(['b', 'a'], dtype='object')

   In [6]: idx.intersection(idx, sort=True)
   Out[6]: Index(['b', 'a'], dtype='object')

New Behavior

.. ipython:: python

   idx.intersection(idx)  # sort=False by default
   idx.intersection(idx, sort=True)

Fixed Regressions

• Bug in :meth:`DataFrame.itertuples` with records orient raising an AttributeError when the DataFrame contained more than 255 columns (:issue:`24939`)
• Bug in :meth:`DataFrame.itertuples` orient converting integer column names to strings prepended with an underscore (:issue:`24940`)
• Fixed regression in :class:`Index.intersection` incorrectly sorting the values by default (:issue:`24959`).
• Fixed regression in :func:`merge` when merging an empty DataFrame with multiple timezone-aware columns on one of the timezone-aware columns (:issue:`25014`).

Enhancements

Bug Fixes

Conversion

Indexing

I/O

Categorical

Timezones

Timedelta - Bug in :func:`to_timedelta` with box=False incorrectly returning a datetime64 object instead of a timedelta64 object (:issue:`24961`) - - -

Reshaping

• Bug in :meth:`DataFrame.groupby` with :class:`Grouper` when there is a time change (DST) and grouping frequency is '1d' (:issue:`24972`)

Visualization

• Fixed the warning for implicitly registered matplotlib converters not showing. See :ref:`whatsnew_0211.converters` for more (:issue:`24963`).

Other

Contributors

.. contributors:: v0.24.0..v0.24.1