v0.5.0.rst

Version 0.5.0 (October 24, 2011)

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New features

• :ref:`Added <basics.df_join>` DataFrame.align method with standard join options
• :ref:`Added <io.parse_dates>` parse_dates option to read_csv and read_table methods to optionally try to parse dates in the index columns
• :ref:`Added <io.parse_dates>` nrows, chunksize, and iterator arguments to read_csv and read_table. The last two return a new TextParser class capable of lazily iterating through chunks of a flat file (:issue:`242`)
• :ref:`Added <merging.multikey_join>` ability to join on multiple columns in DataFrame.join (:issue:`214`)
• Added private _get_duplicates function to Index for identifying duplicate values more easily (ENH5c)
• :ref:`Added <indexing.df_cols>` column attribute access to DataFrame.
• :ref:`Added <indexing.df_cols>` Python tab completion hook for DataFrame columns. (:issue:`233`, :issue:`230`)
• :ref:`Implemented <basics.describe>` Series.describe for Series containing objects (:issue:`241`)
• :ref:`Added <merging.df_inner_join>` inner join option to DataFrame.join when joining on key(s) (:issue:`248`)
• :ref:`Implemented <indexing.df_cols>` selecting DataFrame columns by passing a list to __getitem__ (:issue:`253`)
• :ref:`Implemented <indexing.set_ops>` & and | to intersect / union Index objects, respectively (:issue:`261`)
• :ref:`Added<reshaping.pivot>` pivot_table convenience function to pandas namespace (:issue:`234`)
• :ref:`Implemented <basics.rename_axis>` Panel.rename_axis function (:issue:`243`)
• DataFrame will show index level names in console output (:issue:`334`)
• :ref:`Implemented <advanced.take>` Panel.take
• :ref:`Added<basics.console_output>` set_eng_float_format for alternate DataFrame floating point string formatting (ENH61)
• :ref:`Added <indexing.set_index>` convenience set_index function for creating a DataFrame index from its existing columns
• :ref:`Implemented <groupby.multiindex>` groupby hierarchical index level name (:issue:`223`)
• :ref:`Added <io.store_in_csv>` support for different delimiters in DataFrame.to_csv (:issue:`244`)

Performance enhancements

• VBENCH Major performance improvements in file parsing functions read_csv and read_table
• VBENCH Added Cython function for converting tuples to ndarray very fast. Speeds up many MultiIndex-related operations
• VBENCH Refactored merging / joining code into a tidy class and disabled unnecessary computations in the float/object case, thus getting about 10% better performance (:issue:`211`)
• VBENCH Improved speed of DataFrame.xs on mixed-type DataFrame objects by about 5x, regression from 0.3.0 (:issue:`215`)
• VBENCH With new DataFrame.align method, speeding up binary operations between differently-indexed DataFrame objects by 10-25%.
• VBENCH Significantly sped up conversion of nested dict into DataFrame (:issue:`212`)
• VBENCH Significantly speed up DataFrame __repr__ and count on large mixed-type DataFrame objects

Contributors

.. contributors:: v0.4.0..v0.5.0