Deprecations

plot_date ^^^^^^^^^^^^^

Use of ~.Axes.plot_date has been discouraged since Matplotlib 3.5 and the function is now formally deprecated.

datetime-like data should directly be plotted using ~.Axes.plot.
If you need to plot plain numeric data as :ref:date-format or need to set a timezone, call ax.xaxis.axis_date / ax.yaxis.axis_date before ~.Axes.plot. See .Axis.axis_date.

Legend labels for plot ^^^^^^^^^^^^^^^^^^^^^^^^^^

Previously if a sequence was passed to the label parameter of ~.Axes.plot when plotting a single dataset, the sequence was automatically cast to string for the legend label. This behavior is now deprecated and in future will error if the sequence length is not one (consistent with multi-dataset behavior, where the number of elements must match the number of datasets). To keep the old behavior, cast the sequence to string before passing.

boxplot tick labels ^^^^^^^^^^^^^^^^^^^^^^^

The parameter labels has been renamed to tick_labels for clarity and consistency with ~.Axes.bar.

Mixing positional and keyword arguments for legend handles and labels ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This previously only raised a warning, but is now formally deprecated. If passing handles and labels, they must be passed either both positionally or both as keyword.

Applying theta transforms in PolarTransform ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Applying theta transforms in ~matplotlib.projections.polar.PolarTransform and ~matplotlib.projections.polar.InvertedPolarTransform is deprecated, and will be removed in a future version of Matplotlib. This is currently the default behaviour when these transforms are used externally, but only takes affect when:

An axis is associated with the transform.
The axis has a non-zero theta offset or has theta values increasing in a clockwise direction.

To silence this warning and adopt future behaviour, set apply_theta_transforms=False. If you need to retain the behaviour where theta values are transformed, chain the PolarTransform with a ~matplotlib.transforms.Affine2D transform that performs the theta shift and/or sign shift.

interval parameter of TimerBase.start ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Setting the timer interval while starting it is deprecated. The interval can be specified instead in the timer constructor, or by setting the timer.interval attribute.

nth_coord parameter to axisartist helpers for fixed axis ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Helper APIs in .axisartist for generating a "fixed" axis on rectilinear axes (.FixedAxisArtistHelperRectilinear) no longer take a nth_coord parameter, as that parameter is entirely inferred from the (required) loc parameter and having inconsistent nth_coord and loc is an error.

For curvilinear axes, the nth_coord parameter remains supported (it affects the ticks, not the axis position itself), but that parameter will become keyword-only, for consistency with the rectilinear case.

rcsetup.interactive_bk, rcsetup.non_interactive_bk and rcsetup.all_backends ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

... are deprecated and replaced by matplotlib.backends.backend_registry.list_builtin with the following arguments

matplotlib.backends.BackendFilter.INTERACTIVE
matplotlib.backends.BackendFilter.NON_INTERACTIVE
None

respectively.

Miscellaneous deprecations ^^^^^^^^^^^^^^^^^^^^^^^^^^

backend_ps.get_bbox_header is considered an internal helper
BboxTransformToMaxOnly; if you rely on this, please make a copy of the code
ContourLabeler.add_label_clabeltext
TransformNode.is_bbox; instead check the object using isinstance(..., BboxBase)
GridHelperCurveLinear.get_tick_iterator