Version 0.19.1 (November 3, 2016)#
This is a minor bug-fix release from 0.19.0 and includes some small regression fixes, bug fixes and performance improvements. We recommend that all users upgrade to this version.
What’s new in v0.19.1
Performance improvements#
- Fixed performance regression in factorization of - Perioddata (GH14338)
- Fixed performance regression in - Series.asof(where)when- whereis a scalar (GH14461)
- Improved performance in - DataFrame.asof(where)when- whereis a scalar (GH14461)
- Improved performance in - .to_json()when- lines=True(GH14408)
- Improved performance in certain types of - locindexing with a MultiIndex (GH14551).
Bug fixes#
- Source installs from PyPI will now again work without - cythoninstalled, as in previous versions (GH14204)
- Compat with Cython 0.25 for building (GH14496) 
- Fixed regression where user-provided file handles were closed in - read_csv(c engine) (GH14418).
- Fixed regression in - DataFrame.quantilewhen missing values where present in some columns (GH14357).
- Fixed regression in - Index.differencewhere the- freqof a- DatetimeIndexwas incorrectly set (GH14323)
- Added back - pandas.core.common.array_equivalentwith a deprecation warning (GH14555).
- Bug in - pd.read_csvfor the C engine in which quotation marks were improperly parsed in skipped rows (GH14459)
- Bug in - pd.read_csvfor Python 2.x in which Unicode quote characters were no longer being respected (GH14477)
- Fixed regression in - Index.appendwhen categorical indices were appended (GH14545).
- Fixed regression in - pd.DataFramewhere constructor fails when given dict with- Nonevalue (GH14381)
- Fixed regression in - DatetimeIndex._maybe_cast_slice_boundwhen index is empty (GH14354).
- Bug in localizing an ambiguous timezone when a boolean is passed (GH14402) 
- Bug in - TimedeltaIndexaddition with a Datetime-like object where addition overflow in the negative direction was not being caught (GH14068, GH14453)
- Bug in string indexing against data with - object- Indexmay raise- AttributeError(GH14424)
- Correctly raise - ValueErroron empty input to- pd.eval()and- df.query()(GH13139)
- Bug in - RangeIndex.intersectionwhen result is a empty set (GH14364).
- Bug in groupby-transform broadcasting that could cause incorrect dtype coercion (GH14457) 
- Bug in - Series.__setitem__which allowed mutating read-only arrays (GH14359).
- Bug in - DataFrame.insertwhere multiple calls with duplicate columns can fail (GH14291)
- pd.merge()will raise- ValueErrorwith non-boolean parameters in passed boolean type arguments (GH14434)
- Bug in - Timestampwhere dates very near the minimum (1677-09) could underflow on creation (GH14415)
- Bug in - pd.concatwhere names of the- keyswere not propagated to the resulting- MultiIndex(GH14252)
- Bug in - pd.concatwhere- axiscannot take string parameters- 'rows'or- 'columns'(GH14369)
- Bug in - pd.concatwith dataframes heterogeneous in length and tuple- keys(GH14438)
- Bug in - MultiIndex.set_levelswhere illegal level values were still set after raising an error (GH13754)
- Bug in - DataFrame.to_jsonwhere- lines=Trueand a value contained a- }character (GH14391)
- Bug in - df.groupbycausing an- AttributeErrorwhen grouping a single index frame by a column and the index level (GH14327)
- Bug in - df.groupbywhere- TypeErrorraised when- pd.Grouper(key=...)is passed in a list (GH14334)
- Bug in - pd.pivot_tablemay raise- TypeErroror- ValueErrorwhen- indexor- columnsis not scalar and- valuesis not specified (GH14380)
Contributors#
A total of 30 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.
- Adam Chainz + 
- Anthonios Partheniou 
- Arash Rouhani + 
- Ben Kandel 
- Brandon M. Burroughs + 
- Chris 
- Chris Warth 
- David Krych + 
- Iván Vallés Pérez + 
- Jeff Reback 
- Joe Jevnik 
- Jon M. Mease + 
- Jon Mease + 
- Joris Van den Bossche 
- Josh Owen + 
- Keshav Ramaswamy + 
- Larry Ren + 
- Michael Felt + 
- Piotr Chromiec + 
- Robert Bradshaw + 
- Sinhrks 
- Thiago Serafim + 
- Tom Bird 
- bkandel + 
- chris-b1 
- dubourg + 
- gfyoung 
- mattrijk + 
- paul-mannino + 
- sinhrks