What’s new in 2.0.1 (April 24, 2023)

These are the changes in pandas 2.0.1. See Release notes for a full changelog including other versions of pandas.

Fixed regressions

• Fixed regression for subclassed Series when constructing from a dictionary (GH 52445)

• Fixed regression in SeriesGroupBy.agg() failing when grouping with categorical data, multiple groupings, as_index=False, and a list of aggregations (GH 52760)

• Fixed regression in DataFrame.pivot() changing Index name of input object (GH 52629)

• Fixed regression in DataFrame.resample() raising on a DataFrame with no columns (GH 52484)

• Fixed regression in DataFrame.sort_values() not resetting index when DataFrame is already sorted and ignore_index=True (GH 52553)

• Fixed regression in MultiIndex.isin() raising TypeError for Generator (GH 52568)

• Fixed regression in Series.describe() showing RuntimeWarning for extension dtype Series with one element (GH 52515)

• Fixed regression when adding a new column to a DataFrame when the DataFrame.columns was a RangeIndex and the new key was hashable but not a scalar (GH 52652)

Bug fixes

• Bug in Series.dt.days that would overflow int32 number of days (GH 52391)

• Bug in arrays.DatetimeArray constructor returning an incorrect unit when passed a non-nanosecond numpy datetime array (GH 52555)

• Bug in ArrowExtensionArray with duration dtype overflowing when constructed from data containing numpy NaT (GH 52843)

• Bug in Series.dt.round() when passing a freq of equal or higher resolution compared to the Series would raise a ZeroDivisionError (GH 52761)

• Bug in Series.median() with ArrowDtype returning an approximate median (GH 52679)

• Bug in api.interchange.from_dataframe() was unnecessarily raising on categorical dtypes (GH 49889)

• Bug in api.interchange.from_dataframe() was unnecessarily raising on large string dtypes (GH 52795)

• Bug in pandas.testing.assert_series_equal() where check_dtype=False would still raise for datetime or timedelta types with different resolutions (GH 52449)

• Bug in read_csv() casting PyArrow datetimes to NumPy when dtype_backend="pyarrow" and parse_dates is set causing a performance bottleneck in the process (GH 52546)

• Bug in to_datetime() and to_timedelta() when trying to convert numeric data with a ArrowDtype (GH 52425)

• Bug in to_numeric() with errors='coerce' and dtype_backend='pyarrow' with ArrowDtype data (GH 52588)

• Bug in ArrowDtype.__from_arrow__() not respecting if dtype is explicitly given (GH 52533)

• Bug in DataFrame.describe() not respecting ArrowDtype in include and exclude (GH 52570)

• Bug in DataFrame.max() and related casting different Timestamp resolutions always to nanoseconds (GH 52524)

• Bug in Series.describe() not returning ArrowDtype with pyarrow.float64 type with numeric data (GH 52427)

• Bug in Series.dt.tz_localize() incorrectly localizing timestamps with ArrowDtype (GH 52677)

• Bug in arithmetic between np.datetime64 and np.timedelta64 NaT scalars with units always returning nanosecond resolution (GH 52295)

• Bug in logical and comparison operations between ArrowDtype and numpy masked types (e.g. "boolean") (GH 52625)

• Fixed bug in merge() when merging with ArrowDtype one one and a NumPy dtype on the other side (GH 52406)

• Fixed segfault in Series.to_numpy() with null[pyarrow] dtype (GH 52443)

Other

• DataFrame created from empty dicts had columns of dtype object. It is now a RangeIndex (GH 52404)

• Series created from empty dicts had index of dtype object. It is now a RangeIndex (GH 52404)

• Implemented Series.str.split() and Series.str.rsplit() for ArrowDtype with pyarrow.string (GH 52401)

• Implemented most str accessor methods for ArrowDtype with pyarrow.string (GH 52401)

• Supplying a non-integer hashable key that tests False in api.types.is_scalar() now raises a KeyError for RangeIndex.get_loc(), like it does for Index.get_loc(). Previously it raised an InvalidIndexError (GH 52652).

Contributors

A total of 20 people contributed patches to this release. People with a “+” by their names contributed a patch for the first time.

• Alex Malins +

• Chris Carini +

• Dea María Léon

• Joris Van den Bossche

• Luke Manley

• Marc Garcia

• Marco Edward Gorelli

• MarcoGorelli

• Matthew Roeschke

• MeeseeksMachine

• Natalia Mokeeva

• Nirav +

• Pandas Development Team

• Patrick Hoefler

• Richard Shadrach

• Stefanie Molin

• Terji Petersen

• Thomas +

• Thomas Li

• yonashub