v1.0.1.rst

What's new in 1.0.1 (February 5, 2020)

These are the changes in pandas 1.0.1. See :ref:`release` for a full changelog including other versions of pandas.

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Fixed regressions

• Fixed regression in :class:`DataFrame` setting values with a slice (e.g. df[-4:] = 1) indexing by label instead of position (:issue:`31469`)
• Fixed regression when indexing a Series or DataFrame indexed by DatetimeIndex with a slice containing a :class:`datetime.date` (:issue:`31501`)
• Fixed regression in DataFrame.__setitem__ raising an AttributeError with a :class:`MultiIndex` and a non-monotonic indexer (:issue:`31449`)
• Fixed regression in :class:`Series` multiplication when multiplying a numeric :class:`Series` with >10000 elements with a timedelta-like scalar (:issue:`31457`)
• Fixed regression in .groupby().agg() raising an AssertionError for some reductions like min on object-dtype columns (:issue:`31522`)
• Fixed regression in .groupby() aggregations with categorical dtype using Cythonized reduction functions (e.g. first) (:issue:`31450`)
• Fixed regression in :meth:`.DataFrameGroupBy.apply` and :meth:`.SeriesGroupBy.apply` if called with a function which returned a non-pandas non-scalar object (e.g. a list or numpy array) (:issue:`31441`)
• Fixed regression in :meth:`DataFrame.groupby` whereby taking the minimum or maximum of a column with period dtype would raise a TypeError. (:issue:`31471`)
• Fixed regression in :meth:`DataFrame.groupby` with an empty DataFrame grouping by a level of a MultiIndex (:issue:`31670`).
• Fixed regression in :meth:`DataFrame.apply` with object dtype and non-reducing function (:issue:`31505`)
• Fixed regression in :meth:`to_datetime` when parsing non-nanosecond resolution datetimes (:issue:`31491`)
• Fixed regression in :meth:`~DataFrame.to_csv` where specifying an na_rep might truncate the values written (:issue:`31447`)
• Fixed regression in :class:`Categorical` construction with numpy.str_ categories (:issue:`31499`)
• Fixed regression in :meth:`DataFrame.loc` and :meth:`DataFrame.iloc` when selecting a row containing a single datetime64 or timedelta64 column (:issue:`31649`)
• Fixed regression where setting :attr:`pd.options.display.max_colwidth` was not accepting negative integer. In addition, this behavior has been deprecated in favor of using None (:issue:`31532`)
• Fixed regression in objTOJSON.c fix return-type warning (:issue:`31463`)
• Fixed regression in :meth:`qcut` when passed a nullable integer. (:issue:`31389`)
• Fixed regression in assigning to a :class:`Series` using a nullable integer dtype (:issue:`31446`)
• Fixed performance regression when indexing a DataFrame or Series with a :class:`MultiIndex` for the index using a list of labels (:issue:`31648`)
• Fixed regression in :meth:`read_csv` used in file like object RawIOBase is not recognize encoding option (:issue:`31575`)

Deprecations

• Support for negative integer for :attr:`pd.options.display.max_colwidth` is deprecated in favor of using None (:issue:`31532`)

Bug fixes

Datetimelike

• Fixed bug in :meth:`to_datetime` raising when cache=True and out-of-bound values are present (:issue:`31491`)

Numeric

• Bug in dtypes being lost in DataFrame.__invert__ (~ operator) with mixed dtypes (:issue:`31183`) and for extension-array backed Series and DataFrame (:issue:`23087`)

Plotting

• Plotting tz-aware timeseries no longer gives UserWarning (:issue:`31205`)

Interval

• Bug in :meth:`Series.shift` with interval dtype raising a TypeError when shifting an interval array of integers or datetimes (:issue:`34195`)

Contributors

.. contributors:: v1.0.0..v1.0.1|HEAD