v0.25.1.rst

What's new in 0.25.1 (July XX, 2019)

Enhancements

Other enhancements

Bug fixes

Categorical

Datetimelike

• Bug in :func:`to_datetime` where passing a timezone-naive :class:`DatetimeArray` or :class:`DatetimeIndex` and utc=True would incorrectly return a timezone-naive result (:issue:`27733`)

Timedelta

Timezones

• Bug in :class:`Index` where a numpy object array with a timezone aware :class:`Timestamp` and np.nan would not return a :class:`DatetimeIndex` (:issue:`27011`)

Numeric

• Bug in :meth:`Series.interpolate` when using a timezone aware :class:`DatetimeIndex` (:issue:`27548`)
• Bug when printing negative floating point complex numbers would raise an IndexError (:issue:`27484`)

Conversion

• Improved the warnings for the deprecated methods :meth:`Series.real` and :meth:`Series.imag` (:issue:`27610`)

Strings

Interval

• Bug in :class:`IntervalIndex` where dir(obj) would raise ValueError (:issue:`27571`)

Indexing

• Bug in partial-string indexing returning a NumPy array rather than a Series when indexing with a scalar like .loc['2015'] (:issue:`27516`)
• Break reference cycle involving :class:`Index` and other index classes to allow garbage collection of index objects without running the GC. (:issue:`27585`, :issue:`27840`)
• Fix regression in assigning values to a single column of a DataFrame with a MultiIndex columns (:issue:`27841`).

Missing

MultiIndex

I/O

• Avoid calling S3File.s3 when reading parquet, as this was removed in s3fs version 0.3.0 (:issue:`27756`)
• Better error message when a negative header is passed in :func:`pandas.read_csv` (:issue:`27779`)

Plotting

• Added a pandas_plotting_backends entrypoint group for registering plot backends. See :ref:`extending.plotting-backends` for more (:issue:`26747`).
• Fix compatibility issue with matplotlib when passing a pandas Index to a plot call (:issue:`27775`).

Groupby/resample/rolling

• Bug in :meth:`pandas.core.groupby.DataFrameGroupBy.transform` where applying a timezone conversion lambda function would drop timezone information (:issue:`27496`)
• Bug in windowing over read-only arrays (:issue:`27766`)
• Fixed segfault in pandas.core.groupby.DataFrameGroupBy.quantile when an invalid quantile was passed (:issue:`27470`)

Reshaping

• A KeyError is now raised if .unstack() is called on a :class:`Series` or :class:`DataFrame` with a flat :class:`Index` passing a name which is not the correct one (:issue:`18303`)
• Bug in :meth:`DataFrame.crosstab` when margins set to True and normalize is not False, an error is raised. (:issue:`27500`)
• :meth:`DataFrame.join` now suppresses the FutureWarning when the sort parameter is specified (:issue:`21952`)
• Bug in :meth:`DataFrame.join` raising with readonly arrays (:issue:`27943`)

Sparse

• Bug in reductions for :class:`Series` with Sparse dtypes (:issue:`27080`)

Build Changes

ExtensionArray

Other

• Bug in :meth:`Series.replace` and :meth:`DataFrame.replace` when replacing timezone-aware timestamps using a dict-like replacer (:issue:`27720`)

Contributors

.. contributors:: v0.25.0..HEAD