v2.0.1.rst

What's new in 2.0.1 (April 24, 2023)

These are the changes in pandas 2.0.1. See :ref:`release` for a full changelog including other versions of pandas.

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Fixed regressions

• Fixed regression for subclassed Series when constructing from a dictionary (:issue:`52445`)
• Fixed regression in :meth:`.SeriesGroupBy.agg` failing when grouping with categorical data, multiple groupings, as_index=False, and a list of aggregations (:issue:`52760`)
• Fixed regression in :meth:`DataFrame.pivot` changing :class:`Index` name of input object (:issue:`52629`)
• Fixed regression in :meth:`DataFrame.resample` raising on a DataFrame with no columns (:issue:`52484`)
• Fixed regression in :meth:`DataFrame.sort_values` not resetting index when :class:`DataFrame` is already sorted and ignore_index=True (:issue:`52553`)
• Fixed regression in :meth:`MultiIndex.isin` raising TypeError for Generator (:issue:`52568`)
• Fixed regression in :meth:`Series.describe` showing RuntimeWarning for extension dtype :class:`Series` with one element (:issue:`52515`)
• Fixed regression when adding a new column to a :class:`DataFrame` when the :attr:`DataFrame.columns` was a :class:`RangeIndex` and the new key was hashable but not a scalar (:issue:`52652`)

Bug fixes

• Bug in :attr:`Series.dt.days` that would overflow int32 number of days (:issue:`52391`)
• Bug in :class:`arrays.DatetimeArray` constructor returning an incorrect unit when passed a non-nanosecond numpy datetime array (:issue:`52555`)
• Bug in :class:`~arrays.ArrowExtensionArray` with duration dtype overflowing when constructed from data containing numpy NaT (:issue:`52843`)
• Bug in :func:`Series.dt.round` when passing a freq of equal or higher resolution compared to the :class:`Series` would raise a ZeroDivisionError (:issue:`52761`)
• Bug in :func:`Series.median` with :class:`ArrowDtype` returning an approximate median (:issue:`52679`)
• Bug in :func:`api.interchange.from_dataframe` was unnecessarily raising on categorical dtypes (:issue:`49889`)
• Bug in :func:`api.interchange.from_dataframe` was unnecessarily raising on large string dtypes (:issue:`52795`)
• Bug in :func:`pandas.testing.assert_series_equal` where check_dtype=False would still raise for datetime or timedelta types with different resolutions (:issue:`52449`)
• Bug in :func:`read_csv` casting PyArrow datetimes to NumPy when dtype_backend="pyarrow" and parse_dates is set causing a performance bottleneck in the process (:issue:`52546`)
• Bug in :func:`to_datetime` and :func:`to_timedelta` when trying to convert numeric data with a :class:`ArrowDtype` (:issue:`52425`)
• Bug in :func:`to_numeric` with errors='coerce' and dtype_backend='pyarrow' with :class:`ArrowDtype` data (:issue:`52588`)
• Bug in :meth:`ArrowDtype.__from_arrow__` not respecting if dtype is explicitly given (:issue:`52533`)
• Bug in :meth:`DataFrame.describe` not respecting ArrowDtype in include and exclude (:issue:`52570`)
• Bug in :meth:`DataFrame.max` and related casting different :class:`Timestamp` resolutions always to nanoseconds (:issue:`52524`)
• Bug in :meth:`Series.describe` not returning :class:`ArrowDtype` with pyarrow.float64 type with numeric data (:issue:`52427`)
• Bug in :meth:`Series.dt.tz_localize` incorrectly localizing timestamps with :class:`ArrowDtype` (:issue:`52677`)
• Bug in arithmetic between np.datetime64 and np.timedelta64 NaT scalars with units always returning nanosecond resolution (:issue:`52295`)
• Bug in logical and comparison operations between :class:`ArrowDtype` and numpy masked types (e.g. "boolean") (:issue:`52625`)
• Fixed bug in :func:`merge` when merging with ArrowDtype one one and a NumPy dtype on the other side (:issue:`52406`)
• Fixed segfault in :meth:`Series.to_numpy` with null[pyarrow] dtype (:issue:`52443`)

Other

• :class:`DataFrame` created from empty dicts had :attr:`~DataFrame.columns` of dtype object. It is now a :class:`RangeIndex` (:issue:`52404`)
• :class:`Series` created from empty dicts had :attr:`~Series.index` of dtype object. It is now a :class:`RangeIndex` (:issue:`52404`)
• Implemented :meth:`Series.str.split` and :meth:`Series.str.rsplit` for :class:`ArrowDtype` with pyarrow.string (:issue:`52401`)
• Implemented most str accessor methods for :class:`ArrowDtype` with pyarrow.string (:issue:`52401`)
• Supplying a non-integer hashable key that tests False in :func:`api.types.is_scalar` now raises a KeyError for :meth:`RangeIndex.get_loc`, like it does for :meth:`Index.get_loc`. Previously it raised an InvalidIndexError (:issue:`52652`).

Contributors

.. contributors:: v2.0.0..v2.0.1