Version 0.19.2 (December 24, 2016) — pandas 3.0.0.dev0+2104.ge637b4290d documentation (original) (raw)

This is a minor bug-fix release in the 0.19.x series and includes some small regression fixes, bug fixes and performance improvements. We recommend that all users upgrade to this version.

Highlights include:

• Compatibility with Python 3.6
• Added a Pandas Cheat Sheet. (GH 13202).

What’s new in v0.19.2

• Enhancements
• Performance improvements
• Bug fixes
• Contributors

Enhancements#

The pd.merge_asof(), added in 0.19.0, gained some improvements:

• pd.merge_asof() gained left_index/right_index and left_by/right_by arguments (GH 14253)
• pd.merge_asof() can take multiple columns in by parameter and has specialized dtypes for better performance (GH 13936)

Performance improvements#

• Performance regression with PeriodIndex (GH 14822)
• Performance regression in indexing with getitem (GH 14930)
• Improved performance of .replace() (GH 12745)
• Improved performance Series creation with a datetime index and dictionary data (GH 14894)

Bug fixes#

• Compat with python 3.6 for pickling of some offsets (GH 14685)
• Compat with python 3.6 for some indexing exception types (GH 14684, GH 14689)
• Compat with python 3.6 for deprecation warnings in the test suite (GH 14681)
• Compat with python 3.6 for Timestamp pickles (GH 14689)
• Compat with dateutil==2.6.0; segfault reported in the testing suite (GH 14621)
• Allow nanoseconds in Timestamp.replace as a kwarg (GH 14621)
• Bug in pd.read_csv in which aliasing was being done for na_values when passed in as a dictionary (GH 14203)
• Bug in pd.read_csv in which column indices for a dict-like na_values were not being respected (GH 14203)
• Bug in pd.read_csv where reading files fails, if the number of headers is equal to the number of lines in the file (GH 14515)
• Bug in pd.read_csv for the Python engine in which an unhelpful error message was being raised when multi-char delimiters were not being respected with quotes (GH 14582)
• Fix bugs (GH 14734, GH 13654) in pd.read_sas and pandas.io.sas.sas7bdat.SAS7BDATReader that caused problems when reading a SAS file incrementally.
• Bug in pd.read_csv for the Python engine in which an unhelpful error message was being raised when skipfooter was not being respected by Python’s CSV library (GH 13879)
• Bug in .fillna() in which timezone aware datetime64 values were incorrectly rounded (GH 14872)
• Bug in .groupby(..., sort=True) of a non-lexsorted MultiIndex when grouping with multiple levels (GH 14776)
• Bug in pd.cut with negative values and a single bin (GH 14652)
• Bug in pd.to_numeric where a 0 was not unsigned on a downcast='unsigned' argument (GH 14401)
• Bug in plotting regular and irregular timeseries using shared axes (sharex=True or ax.twinx()) (GH 13341, GH 14322).
• Bug in not propagating exceptions in parsing invalid datetimes, noted in python 3.6 (GH 14561)
• Bug in resampling a DatetimeIndex in local TZ, covering a DST change, which would raise AmbiguousTimeError (GH 14682)
• Bug in indexing that transformed RecursionError into KeyError or IndexingError (GH 14554)
• Bug in HDFStore when writing a MultiIndex when using data_columns=True (GH 14435)
• Bug in HDFStore.append() when writing a Series and passing a min_itemsize argument containing a value for the index (GH 11412)
• Bug when writing to a HDFStore in table format with a min_itemsize value for the index and without asking to append (GH 10381)
• Bug in Series.groupby.nunique() raising an IndexError for an empty Series (GH 12553)
• Bug in DataFrame.nlargest and DataFrame.nsmallest when the index had duplicate values (GH 13412)
• Bug in clipboard functions on linux with python2 with unicode and separators (GH 13747)
• Bug in clipboard functions on Windows 10 and python 3 (GH 14362, GH 12807)
• Bug in .to_clipboard() and Excel compat (GH 12529)
• Bug in DataFrame.combine_first() for integer columns (GH 14687).
• Bug in pd.read_csv() in which the dtype parameter was not being respected for empty data (GH 14712)
• Bug in pd.read_csv() in which the nrows parameter was not being respected for large input when using the C engine for parsing (GH 7626)
• Bug in pd.merge_asof() could not handle timezone-aware DatetimeIndex when a tolerance was specified (GH 14844)
• Explicit check in to_stata and StataWriter for out-of-range values when writing doubles (GH 14618)
• Bug in .plot(kind='kde') which did not drop missing values to generate the KDE Plot, instead generating an empty plot. (GH 14821)
• Bug in unstack() if called with a list of column(s) as an argument, regardless of the dtypes of all columns, they get coerced to object (GH 11847)

Contributors#

A total of 33 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

• Ajay Saxena +
• Ben Kandel
• Chris
• Chris Ham +
• Christopher C. Aycock
• Daniel Himmelstein +
• Dave Willmer +
• Dr-Irv
• Jeff Carey +
• Jeff Reback
• Joe Jevnik
• Joris Van den Bossche
• Julian Santander +
• Kerby Shedden
• Keshav Ramaswamy
• Kevin Sheppard
• Luca Scarabello +
• Matt Roeschke +
• Matti Picus +
• Maximilian Roos
• Mykola Golubyev +
• Nate Yoder +
• Nicholas Ver Halen +
• Pawel Kordek
• Pietro Battiston
• Rodolfo Fernandez +
• Tara Adiseshan +
• Tom Augspurger
• Yaroslav Halchenko
• gfyoung
• hesham.shabana@hotmail.com +
• sinhrks
• wandersoncferreira +