v.0.4.1 through v0.4.3 (September 25 - October 9, 2011)¶

New features¶

Added Python 3 support using 2to3 (GH200)
Added name attribute to Series, now prints as part of Series.__repr__
Added instance methods isnull and notnull to Series (GH209, GH203)
Added Series.align method for aligning two series with choice of join method (ENH56)
Added method get_level_values to MultiIndex (GH188)
Set values in mixed-type DataFrame objects via .ix indexing attribute (GH135)
Added new DataFrame methods get_dtype_counts and property dtypes (ENHdc)
Added ignore_index option to DataFrame.append to stack DataFrames (ENH1b)
read_csv tries to sniff delimiters using csv.Sniffer (GH146)
read_csv can read multiple columns into a MultiIndex; DataFrame’s to_csv method writes out a corresponding MultiIndex (GH151)
DataFrame.rename has a new copy parameter to rename a DataFrame in place (ENHed)
Enable unstacking by name (GH142)
Enable sortlevel to work by level (GH141)

Altered binary operations on differently-indexed SparseSeries objects to use the integer-based (dense) alignment logic which is faster with a larger number of blocks (GH205)
Wrote faster Cython data alignment / merging routines resulting in substantial speed increases
Improved performance of isnull and notnull, a regression from v0.3.0 (GH187)
Refactored code related to DataFrame.join so that intermediate aligned copies of the data in each DataFrame argument do not need to be created. Substantial performance increases result (GH176)
Substantially improved performance of generic Index.intersection and Index.union
Implemented BlockManager.take resulting in significantly faster take performance on mixed-type DataFrame objects (GH104)
Improved performance of Series.sort_index
Significant groupby performance enhancement: removed unnecessary integrity checks in DataFrame internals that were slowing down slicing operations to retrieve groups
Optimized _ensure_index function resulting in performance savings in type-checking Index objects
Wrote fast time series merging / joining methods in Cython. Will be integrated later into DataFrame.join and related functions

A total of 2 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.