What’s new in 2.1.4 (December 8, 2023)

These are the changes in pandas 2.1.4. See Release notes for a full changelog including other versions of pandas.

Fixed regressions

• Fixed regression when trying to read a pickled pandas DataFrame from pandas 1.3 (GH 55137)

Bug fixes

• Bug in Series constructor raising DeprecationWarning when index is a list of Series (GH 55228)

• Bug in Series when trying to cast date-like string inputs to ArrowDtype of pyarrow.timestamp (GH 56266)

• Bug in Timestamp construction with ts_input="now" or ts_input="today" giving a different unit from Timestamp.now() or Timestamp.today() (GH 55879)

• Bug in Index.__getitem__() returning wrong result for Arrow dtypes and negative stepsize (GH 55832)

• Fixed bug in read_csv() not respecting object dtype when infer_string option is set (GH 56047)

• Fixed bug in to_numeric() converting to extension dtype for string[pyarrow_numpy] dtype (GH 56179)

• Fixed bug in DataFrameGroupBy.min() and DataFrameGroupBy.max() not preserving extension dtype for empty object (GH 55619)

• Fixed bug in DataFrame.__setitem__() casting Index with object-dtype to PyArrow backed strings when infer_string option is set (GH 55638)

• Fixed bug in DataFrame.to_hdf() raising when columns have StringDtype (GH 55088)

• Fixed bug in Index.insert() casting object-dtype to PyArrow backed strings when infer_string option is set (GH 55638)

• Fixed bug in Series.__ne__() resulting in False for comparison between NA and string value for dtype="string[pyarrow_numpy]" (GH 56122)

• Fixed bug in Series.mode() not keeping object dtype when infer_string is set (GH 56183)

• Fixed bug in Series.reset_index() not preserving object dtype when infer_string is set (GH 56160)

• Fixed bug in Series.str.split() and Series.str.rsplit() when pat=None for ArrowDtype with pyarrow.string (GH 56271)

• Fixed bug in Series.str.translate() losing object dtype when string option is set (GH 56152)

Contributors

For contributors, please see /usr/share/doc/contributors_list.txt or https://github.com/pandas-dev/pandas/graphs/contributors