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` to allow garbage collection of :class:`Index` objects without running the GC. (:issue:`27585`)

Missing

MultiIndex

I/O

• Avoid calling S3File.s3 when reading parquet, as this was removed in s3fs version 0.3.0 (:issue:`27756`)

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`)

Sparse

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`)

I/O and LZMA

• Issue: Some users may unknowingly have an incomplete Python installation, which lacks the lzma module from the standard library. In this case, import pandas fails due to an ImportError; (:issue: 27575)
• Change: Pandas will now warn, rather than raising an ImportError if the lzma module is not present. Any subsequent attempt to use lzma methods will raise a RuntimeError;
• Possible Fix: Ensure you have the necessary libraries and reinstall Python;
• Example: On MacOS, installing Python with pyenv may lead to an incomplete Python installation due to unmet system dependencies at compilation time (like xz). Compilation will succeed, but Python might fail at run time.

Contributors

.. contributors:: v0.25.0..HEAD