Version 0.5.0 (October 24, 2011)¶
New features¶
Added
DataFrame.align
method with standard join optionsAdded
parse_dates
option toread_csv
andread_table
methods to optionally try to parse dates in the index columnsAdded
nrows
,chunksize
, anditerator
arguments toread_csv
andread_table
. The last two return a newTextParser
class capable of lazily iterating through chunks of a flat file (GH242)Added ability to join on multiple columns in
DataFrame.join
(GH214)Added private
_get_duplicates
function toIndex
for identifying duplicate values more easily (ENH5c)Added column attribute access to DataFrame.
Added Python tab completion hook for DataFrame columns. (GH233, GH230)
Implemented
Series.describe
for Series containing objects (GH241)Added inner join option to
DataFrame.join
when joining on key(s) (GH248)Implemented selecting DataFrame columns by passing a list to
__getitem__
(GH253)Implemented & and | to intersect / union Index objects, respectively (GH261)
Added
pivot_table
convenience function to pandas namespace (GH234)Implemented
Panel.rename_axis
function (GH243)DataFrame will show index level names in console output (GH334)
Implemented
Panel.take
Added
set_eng_float_format
for alternate DataFrame floating point string formatting (ENH61)Added convenience
set_index
function for creating a DataFrame index from its existing columnsImplemented
groupby
hierarchical index level name (GH223)Added support for different delimiters in
DataFrame.to_csv
(GH244)
Performance enhancements¶
VBENCH Major performance improvements in file parsing functions
read_csv
andread_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 (GH211)
VBENCH Improved speed of
DataFrame.xs
on mixed-type DataFrame objects by about 5x, regression from 0.3.0 (GH215)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 (GH212)
VBENCH Significantly speed up DataFrame
__repr__
andcount
on large mixed-type DataFrame objects