These are the changes in pandas 1.6.0. See :ref:`release` for a full changelog including other versions of pandas.
{{ header }}
- :meth:`.DataFrameGroupBy.quantile` and :meth:`.SeriesGroupBy.quantile` now preserve nullable dtypes instead of casting to numpy dtypes (:issue:`37493`)
- :meth:`Series.add_suffix`, :meth:`DataFrame.add_suffix`, :meth:`Series.add_prefix` and :meth:`DataFrame.add_prefix` support an
axisargument. Ifaxisis set, the default behaviour of which axis to consider can be overwritten (:issue:`47819`) - :func:`assert_frame_equal` now shows the first element where the DataFrames differ, analogously to
pytest's output (:issue:`47910`) - Added
indexparameter to :meth:`DataFrame.to_dict` (:issue:`46398`)
These are bug fixes that might have notable behavior changes.
Some minimum supported versions of dependencies were updated. If installed, we now require:
| Package | Minimum Version | Required | Changed |
|---|---|---|---|
| X | X |
For optional libraries the general recommendation is to use the latest version. The following table lists the lowest version per library that is currently being tested throughout the development of pandas. Optional libraries below the lowest tested version may still work, but are not considered supported.
| Package | Minimum Version | Changed |
|---|---|---|
| X |
See :ref:`install.dependencies` and :ref:`install.optional_dependencies` for more.
- Performance improvement in :meth:`.DataFrameGroupBy.median` and :meth:`.SeriesGroupBy.median` for nullable dtypes (:issue:`37493`)
- Performance improvement in :meth:`MultiIndex.argsort` and :meth:`MultiIndex.sort_values` (:issue:`48406`)
- Performance improvement in :meth:`MultiIndex.union` without missing values and without duplicates (:issue:`48505`)
- Performance improvement in :meth:`.DataFrameGroupBy.mean`, :meth:`.SeriesGroupBy.mean`, :meth:`.DataFrameGroupBy.var`, and :meth:`.SeriesGroupBy.var` for extension array dtypes (:issue:`37493`)
- Performance improvement for :meth:`Series.value_counts` with nullable dtype (:issue:`48338`)
- Performance improvement for :class:`Series` constructor passing integer numpy array with nullable dtype (:issue:`48338`)
- Performance improvement in :meth:`DataFrame.loc` and :meth:`Series.loc` for tuple-based indexing of a :class:`MultiIndex` (:issue:`48384`)
- Performance improvement for :meth:`MultiIndex.unique` (:issue:`48335`)
- Performance improvement in
varfor nullable dtypes (:issue:`48379`). - Performance improvement to :func:`read_sas` with
blank_missing=True(:issue:`48502`)
- Bug in :func:`pandas.infer_freq`, raising
TypeErrorwhen inferred on :class:`RangeIndex` (:issue:`47084`)
- Bug in constructing :class:`Series` with
int64dtype from a string list raising instead of casting (:issue:`44923`) - Bug in :meth:`DataFrame.eval` incorrectly raising an
AttributeErrorwhen there are negative values in function call (:issue:`46471`)
- Bug in :meth:`DataFrame.reindex` filling with wrong values when indexing columns and index for
uintdtypes (:issue:`48184`) - Bug in :meth:`DataFrame.reindex` casting dtype to
objectwhen :class:`DataFrame` has single extension array column when re-indexingcolumnsandindex(:issue:`48190`) - Bug in :func:`~DataFrame.describe` when formatting percentiles in the resulting index showed more decimals than needed (:issue:`46362`)
- Bug in :meth:`Index.equals` raising
TypeError` when :class:`Index` consists of tuples that contain ``NA(:issue:`48446`)
- Bug in :meth:`MultiIndex.unique` losing extension array dtype (:issue:`48335`)
- Bug in :meth:`MultiIndex.union` losing extension array (:issue:`48498`, :issue:`48505`, :issue:`48591`)
- Bug in :meth:`MultiIndex.append` not checking names for equality (:issue:`48288`)
- Bug in :meth:`Period.strftime` and :meth:`PeriodIndex.strftime`, raising
UnicodeDecodeErrorwhen a locale-specific directive was passed (:issue:`46319`)
- Bug in :meth:`DataFrameGroupBy.sample` raises
ValueErrorwhen the object is empty (:issue:`48459`)
- Bug in :meth:`DataFrame.pivot` not respecting
Noneas column name (:issue:`48293`) - Bug in :func:`join` when
left_onorright_onis or includes a :class:`CategoricalIndex` incorrectly raisingAttributeError(:issue:`48464`)
- Bug in :meth:`Series.mean` overflowing unnecessarily with nullable integers (:issue:`48378`)
- Bug when concatenating an empty DataFrame with an ExtensionDtype to another DataFrame with the same ExtensionDtype, the resulting dtype turned into object (:issue:`48510`)