Version 0.9.0 (October 7, 2012) — pandas 2.2.3 documentation (original) (raw)

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

In [1]: import io

In [2]: data = """ ...: 0,0,1 ...: 1,1,0 ...: 0,1,0 ...: """ ...:

In [3]: df = pd.read_csv(io.StringIO(data), header=None)

In [4]: df Out[4]: 0 1 2 0 0 0 1 1 1 1 0 2 0 1 0

[3 rows x 3 columns]

• 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:

In [5]: s1 = pd.Series([1, 2, 3])

In [6]: s1 Out[6]: 0 1 1 2 2 3 Length: 3, dtype: int64

In [7]: s2 = pd.Series(s1, index=["foo", "bar", "baz"])

In [8]: s2 Out[8]: foo NaN bar NaN baz NaN Length: 3, dtype: float64

• Deprecated day_of_year API removed from PeriodIndex, use dayofyear(GH 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 (GH 1834, GH 1824)
• Legacy cruft removed: pandas.stats.misc.quantileTS
• Use ISO8601 format for Period repr: monthly, daily, and on down (GH 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) (GH 1783)
• Setting parts of DataFrame/Panel using ix now aligns input Series/DataFrame (GH 1630)
• first and last methods in GroupBy no longer drop non-numeric columns (GH 1809)
• Resolved inconsistencies in specifying custom NA values in text parser.na_values of type dict no longer override default NAs unlesskeep_default_na is set to false explicitly (GH 1657)
• DataFrame.dot will not do data alignment, and also work with Series (GH 1915)

See the full release notes or issue tracker on GitHub for a complete list.

Contributors#

A total of 24 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

• Chang She
• Christopher Whelan +
• Dan Miller +
• Daniel Shapiro +
• Dieter Vandenbussche
• Doug Coleman +
• John-Colvin +
• Johnny +
• Joshua Leahy +
• Lars Buitinck +
• Mark O’Leary +
• Martin Blais
• MinRK +
• Paul Ivanov +
• Skipper Seabold
• Spencer Lyon +
• Taavi Burns +
• Wes McKinney
• Wouter Overmeire
• Yaroslav Halchenko
• lenolib +
• tshauck +
• y-p +
• Øystein S. Haaland +