v0.9.0.rst

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Version 0.9.0 (October 7, 2012)

This is a major release from 0.8.1 and includes several new features and enhancements along with a large number of bug fixes. New features include vectorized unicode encoding/decoding for Series.str, to_latex method to DataFrame, more flexible parsing of boolean values, and enabling the download of options data from Yahoo! Finance.

New features

• Add encode and decode for unicode handling to :ref:`vectorized string processing methods <text.string_methods>` in Series.str (:issue:`1706`)
• Add DataFrame.to_latex method (:issue:`1735`)
• Add convenient expanding window equivalents of all rolling_* ops (:issue:`1785`)
• Add Options class to pandas.io.data for fetching options data from Yahoo! Finance (:issue:`1748`, :issue:`1739`)
• More flexible parsing of boolean values (Yes, No, TRUE, FALSE, etc) (:issue:`1691`, :issue:`1295`)
• Add level parameter to Series.reset_index
• TimeSeries.between_time can now select times across midnight (:issue:`1871`)
• Series constructor can now handle generator as input (:issue:`1679`)
• DataFrame.dropna can now take multiple axes (tuple/list) as input (:issue:`924`)
• Enable skip_footer parameter in ExcelFile.parse (:issue:`1843`)

API changes

• The default column names when header=None and no columns names passed to functions like read_csv has changed to be more Pythonic and amenable to attribute access:

.. ipython:: python

   import io

   data = """
   0,0,1
   1,1,0
   0,1,0
   """
   df = pd.read_csv(io.StringIO(data), header=None)
   df

• Creating a Series from another Series, passing an index, will cause reindexing to happen inside rather than treating the Series like an ndarray. Technically improper usages like Series(df[col1], index=df[col2]) that worked before "by accident" (this was never intended) will lead to all NA Series in some cases. To be perfectly clear:

.. ipython:: python

   s1 = pd.Series([1, 2, 3])
   s1

   s2 = pd.Series(s1, index=["foo", "bar", "baz"])
   s2

• Deprecated day_of_year API removed from PeriodIndex, use dayofyear (:issue:`1723`)
• Don't modify NumPy suppress printoption to True at import time
• The internal HDF5 data arrangement for DataFrames has been transposed. Legacy files will still be readable by HDFStore (:issue:`1834`, :issue:`1824`)
• Legacy cruft removed: pandas.stats.misc.quantileTS
• Use ISO8601 format for Period repr: monthly, daily, and on down (:issue:`1776`)
• Empty DataFrame columns are now created as object dtype. This will prevent a class of TypeErrors that was occurring in code where the dtype of a column would depend on the presence of data or not (e.g. a SQL query having results) (:issue:`1783`)
• Setting parts of DataFrame/Panel using ix now aligns input Series/DataFrame (:issue:`1630`)
• first and last methods in GroupBy no longer drop non-numeric columns (:issue:`1809`)
• Resolved inconsistencies in specifying custom NA values in text parser. na_values of type dict no longer override default NAs unless keep_default_na is set to false explicitly (:issue:`1657`)
• DataFrame.dot will not do data alignment, and also work with Series (:issue:`1915`)

See the :ref:`full release notes <release>` or issue tracker on GitHub for a complete list.

Contributors

.. contributors:: v0.8.1..v0.9.0