What’s new in 1.1.2 (September 8, 2020)#

These are the changes in pandas 1.1.2. See Release notes for a full changelog including other versions of pandas.

Fixed regressions#

  • Regression in DatetimeIndex.intersection() incorrectly raising AssertionError when intersecting against a list (GH 35876)

  • Fix regression in updating a column inplace (e.g. using df['col'].fillna(.., inplace=True)) (GH 35731)

  • Fix regression in DataFrame.append() mixing tz-aware and tz-naive datetime columns (GH 35460)

  • Performance regression for RangeIndex.format() (GH 35712)

  • Regression where MultiIndex.get_loc() would return a slice spanning the full index when passed an empty list (GH 35878)

  • Fix regression in invalid cache after an indexing operation; this can manifest when setting which does not update the data (GH 35521)

  • Regression in DataFrame.replace() where a TypeError would be raised when attempting to replace elements of type Interval (GH 35931)

  • Fix regression in pickle roundtrip of the closed attribute of IntervalIndex (GH 35658)

  • Fixed regression in DataFrameGroupBy.agg() where a ValueError: buffer source array is read-only would be raised when the underlying array is read-only (GH 36014)

  • Fixed regression in Series.groupby.rolling() number of levels of MultiIndex in input was compressed to one (GH 36018)

  • Fixed regression in DataFrameGroupBy on an empty DataFrame (GH 36197)

Bug fixes#

  • Bug in DataFrame.eval() with object dtype column binary operations (GH 35794)

  • Bug in Series constructor raising a TypeError when constructing sparse datetime64 dtypes (GH 35762)

  • Bug in DataFrame.apply() with result_type="reduce" returning with incorrect index (GH 35683)

  • Bug in Series.astype() and DataFrame.astype() not respecting the errors argument when set to "ignore" for extension dtypes (GH 35471)

  • Bug in DateTimeIndex.format() and PeriodIndex.format() with name=True setting the first item to "None" where it should be "" (GH 35712)

  • Bug in Float64Index.__contains__() incorrectly raising TypeError instead of returning False (GH 35788)

  • Bug in Series constructor incorrectly raising a TypeError when passed an ordered set (GH 36044)

  • Bug in Series.dt.isocalendar() and DatetimeIndex.isocalendar() that returned incorrect year for certain dates (GH 36032)

  • Bug in DataFrame indexing returning an incorrect Series in some cases when the series has been altered and a cache not invalidated (GH 33675)

  • Bug in DataFrame.corr() causing subsequent indexing lookups to be incorrect (GH 35882)

  • Bug in import_optional_dependency() returning incorrect package names in cases where package name is different from import name (GH 35948)

  • Bug when setting empty DataFrame column to a Series in preserving name of index in frame (GH 31368)



A total of 16 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

  • Ali McMaster

  • Asish Mahapatra

  • Daniel Saxton

  • Fangchen Li

  • Harsh Sharma +

  • Irv Lustig

  • Jeet Parekh +

  • Joris Van den Bossche

  • Kaiqi Dong

  • Matthew Roeschke

  • MeeseeksMachine

  • Pandas Development Team

  • Simon Hawkins

  • Terji Petersen

  • jbrockmendel

  • patrick