v0.20.2.rst

Version 0.20.2 (June 4, 2017)

{{ header }}

.. ipython:: python
   :suppress:

   from pandas import *  # noqa F401, F403

This is a minor bug-fix release in the 0.20.x series and includes some small regression fixes, bug fixes and performance improvements. We recommend that all users upgrade to this version.

What's new in v0.20.2

• Enhancements
• Performance improvements
• Bug fixes
  • Conversion
  • Indexing
  • IO
  • Plotting
  • GroupBy/resample/rolling
  • Sparse
  • Reshaping
  • Numeric
  • Categorical
  • Other
• Contributors

Enhancements

• Unblocked access to additional compression types supported in pytables: 'blosc:blosclz, 'blosc:lz4', 'blosc:lz4hc', 'blosc:snappy', 'blosc:zlib', 'blosc:zstd' (:issue:`14478`)
• Series provides a to_latex method (:issue:`16180`)
• A new groupby method :meth:`.GroupBy.ngroup`, parallel to the existing :meth:`.GroupBy.cumcount`, has been added to return the group order (:issue:`11642`); see :ref:`here <groupby.ngroup>`.

Performance improvements

• Performance regression fix when indexing with a list-like (:issue:`16285`)
• Performance regression fix for MultiIndexes (:issue:`16319`, :issue:`16346`)
• Improved performance of .clip() with scalar arguments (:issue:`15400`)
• Improved performance of groupby with categorical groupers (:issue:`16413`)
• Improved performance of MultiIndex.remove_unused_levels() (:issue:`16556`)

Bug fixes

• Silenced a warning on some Windows environments about "tput: terminal attributes: No such device or address" when detecting the terminal size. This fix only applies to python 3 (:issue:`16496`)
• Bug in using pathlib.Path or py.path.local objects with io functions (:issue:`16291`)
• Bug in Index.symmetric_difference() on two equal MultiIndex's, results in a TypeError (:issue:`13490`)
• Bug in DataFrame.update() with overwrite=False and NaN values (:issue:`15593`)
• Passing an invalid engine to :func:`read_csv` now raises an informative ValueError rather than UnboundLocalError. (:issue:`16511`)
• Bug in :func:`unique` on an array of tuples (:issue:`16519`)
• Bug in :func:`cut` when labels are set, resulting in incorrect label ordering (:issue:`16459`)
• Fixed a compatibility issue with IPython 6.0's tab completion showing deprecation warnings on Categoricals (:issue:`16409`)

Conversion

• Bug in :func:`to_numeric` in which empty data inputs were causing a segfault of the interpreter (:issue:`16302`)
• Silence numpy warnings when broadcasting DataFrame to Series with comparison ops (:issue:`16378`, :issue:`16306`)

Indexing

• Bug in DataFrame.reset_index(level=) with single level index (:issue:`16263`)
• Bug in partial string indexing with a monotonic, but not strictly-monotonic, index incorrectly reversing the slice bounds (:issue:`16515`)
• Bug in MultiIndex.remove_unused_levels() that would not return a MultiIndex equal to the original. (:issue:`16556`)

IO

• Bug in :func:`read_csv` when comment is passed in a space delimited text file (:issue:`16472`)
• Bug in :func:`read_csv` not raising an exception with nonexistent columns in usecols when it had the correct length (:issue:`14671`)
• Bug that would force importing of the clipboard routines unnecessarily, potentially causing an import error on startup (:issue:`16288`)
• Bug that raised IndexError when HTML-rendering an empty DataFrame (:issue:`15953`)
• Bug in :func:`read_csv` in which tarfile object inputs were raising an error in Python 2.x for the C engine (:issue:`16530`)
• Bug where DataFrame.to_html() ignored the index_names parameter (:issue:`16493`)
• Bug where pd.read_hdf() returns numpy strings for index names (:issue:`13492`)
• Bug in HDFStore.select_as_multiple() where start/stop arguments were not respected (:issue:`16209`)

Plotting

• Bug in DataFrame.plot with a single column and a list-like color (:issue:`3486`)
• Bug in plot where NaT in DatetimeIndex results in Timestamp.min (:issue:`12405`)
• Bug in DataFrame.boxplot where figsize keyword was not respected for non-grouped boxplots (:issue:`11959`)

GroupBy/resample/rolling

• Bug in creating a time-based rolling window on an empty DataFrame (:issue:`15819`)
• Bug in rolling.cov() with offset window (:issue:`16058`)
• Bug in .resample() and .groupby() when aggregating on integers (:issue:`16361`)

Sparse

• Bug in construction of SparseDataFrame from scipy.sparse.dok_matrix (:issue:`16179`)

Reshaping

• Bug in DataFrame.stack with unsorted levels in MultiIndex columns (:issue:`16323`)
• Bug in pd.wide_to_long() where no error was raised when i was not a unique identifier (:issue:`16382`)
• Bug in Series.isin(..) with a list of tuples (:issue:`16394`)
• Bug in construction of a DataFrame with mixed dtypes including an all-NaT column. (:issue:`16395`)
• Bug in DataFrame.agg() and Series.agg() with aggregating on non-callable attributes (:issue:`16405`)

Numeric

• Bug in .interpolate(), where limit_direction was not respected when limit=None (default) was passed (:issue:`16282`)

Categorical

• Fixed comparison operations considering the order of the categories when both categoricals are unordered (:issue:`16014`)

Other

• Bug in DataFrame.drop() with an empty-list with non-unique indices (:issue:`16270`)

Contributors

.. contributors:: v0.20.0..v0.20.2