v0.19.1.txt

.. _whatsnew_0191:

v0.19.1 (????, 2016)
---------------------

This is a minor bug-fix release from 0.19.0 and includes a large number of
bug fixes along with several new features, enhancements, and performance improvements.
We recommend that all users upgrade to this version.

Highlights include:


.. contents:: What's new in v0.19.1
    :local:
    :backlinks: none


.. _whatsnew_0191.performance:

Performance Improvements
~~~~~~~~~~~~~~~~~~~~~~~~

- Fixed performance regression in factorization of ``Period`` data (:issue:`14338`)
- Improved Performance in ``.to_json()`` when ``lines=True`` (:issue:`14408`)




.. _whatsnew_0191.bug_fixes:

Bug Fixes
~~~~~~~~~




- Bug in localizing an ambiguous timezone when a boolean is passed (:issue:`14402`)








- Bug in ``pd.concat`` where names of the ``keys`` were not propagated to the resulting ``MultiIndex`` (:issue:`14252`)
- Bug in ``pd.concat`` where ``axis`` cannot take string parameters ``'rows'`` or ``'columns'`` (:issue:`14369`)
- Bug in ``MultiIndex.set_levels`` where illegal level values were still set after raising an error (:issue:`13754`)
- Bug in ``DataFrame.to_json`` where ``lines=True`` and a value contained a ``}`` character (:issue:`14391`)
- Bug in ``df.groupby`` causing an ``AttributeError`` when grouping a single index frame by a column and the index level (:issue`14327`)
- Bug in ``pd.to_numeric`` where it would not downcast a 0 to a uint8 (:issue:`14404`)
- Bug in ``pd.to_numeric`` where it would not downcast a 0 properly. (:issue:`14401`)
- Bug in ``pd.to_numeric`` where a 0 was not unsigned on a downcast = 'unsigned' argument (:issue:`14401`)