What’s new in 1.4.1 (February 12, 2022)

These are the changes in pandas 1.4.1. See Release notes for a full changelog including other versions of pandas.

Fixed regressions

• Regression in Series.mask() with inplace=True and PeriodDtype and an incompatible other coercing to a common dtype instead of raising (GH45546)

• Regression in assert_frame_equal() not respecting check_flags=False (GH45554)

• Regression in DataFrame.loc() raising ValueError when indexing (getting values) on a MultiIndex with one level (GH45779)

• Regression in Series.fillna() with downcast=False incorrectly downcasting object dtype (GH45603)

• Regression in api.types.is_bool_dtype() raising an AttributeError when evaluating a categorical Series (GH45615)

• Regression in DataFrame.iat() setting values leading to not propagating correctly in subsequent lookups (GH45684)

• Regression when setting values with DataFrame.loc() losing Index name if DataFrame was empty before (GH45621)

• Regression in join() with overlapping IntervalIndex raising an InvalidIndexError (GH45661)

• Regression when setting values with Series.loc() raising with all False indexer and Series on the right hand side (GH45778)

• Regression in read_sql() with a DBAPI2 connection that is not an instance of sqlite3.Connection incorrectly requiring SQLAlchemy be installed (GH45660)

• Regression in DateOffset when constructing with an integer argument with no keywords (e.g. pd.DateOffset(n)) would behave like datetime.timedelta(days=0) (GH45643, GH45890)

Bug fixes

• Fixed segfault in DataFrame.to_json() when dumping tz-aware datetimes in Python 3.10 (GH42130)

• Stopped emitting unnecessary FutureWarning in DataFrame.sort_values() with sparse columns (GH45618)

• Fixed window aggregations in DataFrame.rolling() and Series.rolling() to skip over unused elements (GH45647)

• Fixed builtin highlighters in Styler to be responsive to NA with nullable dtypes (GH45804)

• Bug in apply() with axis=1 raising an erroneous ValueError (GH45912)

Other

• Reverted performance speedup of DataFrame.corr() for method=pearson to fix precision regression (GH45640, GH42761)

Contributors

A total of 19 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

• Adam Bowden +

• JHM Darbyshire

• Johannes Mueller

• John Zangwill

• Jonas Haag

• Matthew Roeschke

• MeeseeksMachine

• Pandas Development Team

• Patrick Hoefler

• Robbie Palmer +

• Simon Hawkins

• Thomas Li

• Tyler Reddy

• eshirvana +

• gesoos +

• hasan-yaman

• jbrockmendel

• partev

• rtpsw +

previous

What’s new in 1.4.2 (April 2, 2022)

next

What’s new in 1.4.0 (January 22, 2022)