v0.19.0 Final

This is a major release from 0.18.1 and includes a number of API changes, several new features, enhancements, and performance improvements along with a large number of bug fixes. We recommend that all users upgrade to this version.

Highlights include:

• merge_asof for asof-style time-series joining, see here
• .rolling() is now time-series aware, see here
• read_csv now supports parsing Categorical data, see here
• A function union_categorical has been added for combining categoricals, see here
• PeriodIndex now has its own period dtype, and changed to be more consistent with other Index classes. See here
• Sparse data structures gained enhanced support of int and bool dtypes, see here
• Comparison operations with Series no longer ignores the index, see here for an overview of the API changes.
• Introduction of a pandas development API for utility functions, see here.
• Deprecation of Panel4D and PanelND. We recommend to represent these types of n-dimensional data with the xarray package.
• Removal of the previously deprecated modules pandas.io.data, pandas.io.wb, pandas.tools.rplot.

See the Whatsnew file for more information.