What's new in 1.0.0 (??)

Warning

Starting with the 0.25.x series of releases, pandas only supports Python 3.5.3 and higher. See Dropping Python 2.7 for more details.

Warning

The minimum supported Python version will be bumped to 3.6 in a future release.

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These are the changes in pandas 1.0.0. See :ref:`release` for a full changelog including other versions of pandas.

Enhancements

:meth:`DataFrame.to_latex` now accepts caption and label arguments (:issue:`25436`)
:meth:`DataFrame.to_string` added the max_colwidth parameter to control when wide columns are truncated (:issue:`9784`)

Other enhancements

Backwards incompatible API changes

:class:`pandas.core.groupby.GroupBy.transform` now raises on invalid operation names (:issue:`27489`).

Other API changes

:meth:`pandas.api.types.infer_dtype` will now return "integer-na" for integer and np.nan mix (:issue:`27283`)

Deprecations

Removal of prior version deprecations/changes

Removed the previously deprecated :meth:`Series.get_value`, :meth:`Series.set_value`, :meth:`DataFrame.get_value`, :meth:`DataFrame.set_value` (:issue:`17739`)
Changed the the default value of inplace in :meth:`DataFrame.set_index` and :meth:`Series.set_axis`. It now defaults to False (:issue:`27600`)
:meth:`pandas.Series.str.cat` now defaults to aligning others, using join='left' (:issue:`27611`)
:meth:`pandas.Series.str.cat` does not accept list-likes within list-likes anymore (:issue:`27611`)
Removed the previously deprecated :meth:`ExtensionArray._formatting_values`. Use :attr:`ExtensionArray._formatter` instead. (:issue:`23601`)
Removed the previously deprecated IntervalIndex.from_intervals in favor of the :class:`IntervalIndex` constructor (:issue:`19263`)

Performance improvements

Performance improvement in indexing with a non-unique :class:`IntervalIndex` (:issue:`27489`)
Performance improvement in MultiIndex.is_monotonic (:issue:`27495`)
Performance improvement in :func:`cut` when bins is an :class:`IntervalIndex` (:issue:`27668`)
Performance improvement in :meth:`DataFrame.replace` when provided a list of values to replace (:issue:`28099`)

Bug fixes

Categorical

Added test to assert the :func:`fillna` raises the correct ValueError message when the value isn't a value from categories (:issue:`13628`)

Datetimelike

Bug in :meth:`Series.__setitem__` incorrectly casting np.timedelta64("NaT") to np.datetime64("NaT") when inserting into a :class:`Series` with datetime64 dtype (:issue:`27311`)
Bug in :meth:`Series.dt` property lookups when the underlying data is read-only (:issue:`27529`)
Bug in HDFStore.__getitem__ incorrectly reading tz attribute created in Python 2 (:issue:`26443`)

Timedelta

Timezones

Numeric

Bug in :meth:`DataFrame.quantile` with zero-column :class:`DataFrame` incorrectly raising (:issue:`23925`)

Conversion

Strings

Interval

Indexing

Bug in assignment using a reverse slicer (:issue:`26939`)

Missing

MultiIndex

I/O

:meth:`read_csv` now accepts binary mode file buffers when using the Python csv engine (:issue:`23779`)
Bug in :meth:`DataFrame.to_json` where using a Tuple as a column or index value and using orient="columns" or orient="index" would produce invalid JSON (:issue:`20500`)
Improve infinity parsing. :meth:`read_csv` now interprets Infinity, +Infinity, -Infinity as floating point values (:issue:`10065`)
Bug in :func:`DataFrame.to_string` where values were truncated using display options instead of outputting the full content (:issue:`9784`)

Plotting

Bug in :meth:`Series.plot` not able to plot boolean values (:issue:`23719`)
Bug in :meth:`DataFrame.plot` producing incorrect legend markers when plotting multiple series on the same axis (:issue:`18222`)
Bug in :meth:`DataFrame.plot` when kind='box' and data contains datetime or timedelta data. These types are now automatically dropped (:issue:`22799`)
Bug in :meth:`DataFrame.plot.line` and :meth:`DataFrame.plot.area` produce wrong xlim in x-axis (:issue:`27686`, :issue:`25160`, :issue:`24784`)
:func:`set_option` now validates that the plot backend provided to 'plotting.backend' implements the backend when the option is set, rather than when a plot is created (:issue:`28163`)

Groupby/resample/rolling

Bug in :meth:`DataFrame.rolling` not allowing for rolling over datetimes when axis=1 (:issue: 28192)
Bug in :meth:`DataFrame.groupby` not offering selection by column name when axis=1 (:issue:`27614`)
Bug in :meth:`DataFrameGroupby.agg` not able to use lambda function with named aggregation (:issue:`27519`)

Reshaping

Sparse

Bug in :class:`SparseDataFrame` arithmetic operations incorrectly casting inputs to float (:issue:`28107`)

Build Changes

Fixed pyqt development dependency issue because of different pyqt package name in conda and PyPI (:issue:`26838`)

ExtensionArray

Other

Trying to set the display.precision, display.max_rows or display.max_columns using :meth:`set_option` to anything but a None or a positive int will raise a ValueError (:issue:`23348`)
Using :meth:`DataFrame.replace` with overlapping keys in a nested dictionary will no longer raise, now matching the behavior of a flat dictionary (:issue:`27660`)
:meth:`DataFrame.to_csv` and :meth:`Series.to_csv` now support dicts as compression argument with key 'method' being the compression method and others as additional compression options when the compression method is 'zip'. (:issue:`26023`)

Contributors