.Formatter.fix_minus now performs hyphen-to-unicode-minus replacement whenever :rc:`axes.unicode_minus` is True; i.e. its behavior matches the one of ScalarFormatter.fix_minus (.ScalarFormatter now just inherits that implementation).

This replacement is now used by the format_data_short method of the various builtin formatter classes, which affects the cursor value in the GUI toolbars.

Previously, it did not necessarily have such an attribute. A check for hasattr(figure.canvas, "manager") should now be replaced by figure.canvas.manager is not None (or getattr(figure.canvas, "manager", None) is not None for back-compatibility).

.cbook.CallbackRegistry now defaults to propagating exceptions thrown by callbacks when no interactive GUI event loop is running. If a GUI event loop is running, .cbook.CallbackRegistry still defaults to just printing a traceback, as unhandled exceptions can make the program completely abort() in that case.

.axes.Axes.locator_params used to accept any value for axis and silently did nothing, when passed an unsupported value. It now raises a ValueError.

.Axis.set_tick_params (and the higher level .axes.Axes.tick_params and .pyplot.tick_params) used to accept any value for which and silently did nothing, when passed an unsupported value. It now raises a ValueError.

If an axis is using a .ticker.FixedLocator, typically set by a call to .Axis.set_ticks, then the number of ticklabels supplied must match the number of locations available (FixedFormattor.locs). If not, a ValueError is raised.

backend_pgf.LatexManager.latex is now created with encoding="utf-8", so its stdin, stdout, and stderr attributes are utf8-encoded.

Previously, passing labels without passing the ticks to either .pyplot.xticks and .pyplot.yticks would result in

TypeError: object of type 'NoneType' has no len()

It now raises a TypeError with a proper description of the error.

Previously, calling e.g. plot(..., color=somecolor, c=othercolor) would emit a warning because color and c actually map to the same Artist property. This now raises a TypeError.

.FileMovieWriter now defaults to writing temporary frames in a temporary directory, which is always cleared at exit. In order to keep the individual frames saved on the filesystem, pass an explicit frame_prefix.

Previously, calling .Axes.plot e.g. with x of shape (n, 3) and y of shape (n, 2) would plot the first column of x against the first column of y, the second column of x against the second column of y, and the first column of x against the third column of y. This now raises an error instead.

This creates the stem plot as a .LineCollection rather than individual .Line2D objects, greatly improving performance.

Previously, rcParams entries whose values were color-like accepted "spurious" extra letters or characters in the "middle" of the string, e.g. "(0, 1a, '0.5')" would be interpreted as (0, 1, 0.5). These extra characters (including the internal quotes) now cause a ValueError to be raised.

Previously, .SymLogNorm had no base kwarg, and defaulted to base=np.e whereas the documentation said it was base=10. In preparation to make the default 10, calling .SymLogNorm without the new base kwarg emits a deprecation warning.

Previously setting the ecolor would turn off automatic color cycling for the plot, leading to the the lines and markers defaulting to whatever the first color in the color cycle was in the case of multiple plot calls.

It previously raised TypeError, except when the input was of the form b"C[number]" in which case it raised a ValueError.

These methods now assume that the figure edge and facecolor have been correctly applied by .FigureCanvasBase.print_figure, as they are normally called through it.

This behavior is consistent with other figure saving methods (.FigureCanvasAgg.print_png, .FigureCanvasPdf.print_pdf, .FigureCanvasSVG.print_svg).

This is consistent with other signature mismatch errors. Previously a ValueError was raised.

Shortcuts for closing all figures now also work for the classic toolbar. There is no default shortcut any more because unintentionally closing all figures by a key press might happen too easily. You can configure the shortcut yourself using :rc:`keymap.quit_all`.

Calling ax.arrow() will now autoscale the axes.

... because the offset text can rarely be interpreted without tick labels anyways.

The parameter s to .Axes.annotate and .pyplot.annotate is renamed to text, matching .Annotation.

The old parameter name remains supported, but support for it will be dropped in a future Matplotlib release.

... to prevent multiple processes from writing to it at the same time.

Previously, keyword arguments were silently ignored when no positional arguments were given.

Previously, .Axis.get_minorticklabels and .Axis.get_majorticklabels returns silent_list. Their return type is now changed to normal list. .get_xminorticklabels, .get_yminorticklabels, .get_zminorticklabels, .Axis.get_ticklabels, .get_xmajorticklabels, .get_ymajorticklabels and .get_zmajorticklabels methods will be affected by this change.

The default method used to format .Slider values has been changed to use a .ScalarFormatter adapted the slider values limits. This should ensure that values are displayed with an appropriate number of significant digits even if they are much smaller or much bigger than 1. To restore the old behavior, explicitly pass a "%1.2f" as the valfmt parameter to .Slider.

pie() used to draw a partial pie if the sum of the values was < 1. This behavior is deprecated and will change to always normalizing the values to a full pie by default. If you want to draw a partial pie, please pass normalize=False explicitly.

All the functionality of CustomCell has been moved to its base class ~.table.Cell.

Setting the timer interval on a not-yet-started TimerWx won't start it anymore.

This ensures that they go above gridlines by default. The old zorder can be kept by passing it as a keyword argument to .Axes.hist.

.Legend and .OffsetBox subclasses (.PaddedBox, .AnchoredOffsetbox, and .AnnotationBbox) no longer directly keep track of the visibility of their underlying .Patch artist, but instead pass that flag down to the .Patch.

This affects legends produced on an Axes (.Axes.legend and .pyplot.legend) and on a Figure (.Figure.legend and .pyplot.figlegend). Figure legends also no longer accept the unsupported 'best' location. Previously, invalid Axes locations would use 'best' and invalid Figure locations would used 'upper right'.

Instead of plt.plot(..., linestyle="steps--"), use plt.plot(..., linestyle="--", drawstyle="steps"). ds is also an alias for drawstyle.

Support for passing single-letter colors (one of "rgbcmykw") as UPPERCASE characters is removed; these colors are now case-sensitive (lowercase).

tight_layout and constrained_layout shrink axes to accommodate "decorations" on the axes. However, if an xlabel or title is too long in the x direction, making the axes smaller in the x-direction doesn't help. The behavior of both has been changed to ignore the width of the title and xlabel and the height of the ylabel in the layout logic.

This also means there is a new keyword argument for .axes.Axes.get_tightbbox and .axis.Axis.get_tightbbox: for_layout_only, which defaults to False, but if True returns a bounding box using the rules above.

This newly allowed value for :rc:`savefig.facecolor` and :rc:`savefig.edgecolor`, as well as the facecolor and edgecolor parameters to .Figure.savefig, means "use whatever facecolor and edgecolor the figure current has".

When .Axes.hist is called with a single dataset, it adds to the axes either a .BarContainer object (when histtype="bar" or "barstacked"), or a .Polygon object (when histype="step" or "stepfilled") -- the latter being wrapped in a list-of-one-element. Previously, either artist would be wrapped in a .silent_list. This is no longer the case: the .BarContainer is now returned as is (this is an API breaking change if you were directly relying on the concrete list API; however, .BarContainer inherits from tuple so most common operations remain available), and the list-of-one .Polygon is returned as is. This makes the repr of the returned artist more accurate: it is now

<BarContainer object of of 10 artists>  # "bar", "barstacked"
[<matplotlib.patches.Polygon object at 0xdeadbeef>]  # "step", "stepfilled"

instead of

<a list of 10 Patch objects>  # "bar", "barstacked"
<a list of 1 Patch objects>  # "step", "stepfilled"

When .Axes.hist is called with multiple artists, it still wraps its return value in a .silent_list, but uses more accurate type information

<a list of 3 BarContainer objects>  # "bar", "barstacked"
<a list of 3 List[Polygon] objects>  # "step", "stepfilled"

instead of

<a list of 3 Lists of Patches objects>  # "bar", "barstacked"
<a list of 3 Lists of Patches objects>  # "step", "stepfilled"

The coordinates information is now displayed in the toolbar, consistently with the other backends. This is intended to simplify embedding of Matplotlib in larger GUIs, where Matplotlib may control the toolbar but not the status bar.

:rc:`text.hinting` now supports the values "default", "no_autohint", "force_autohint", and "no_hinting", which directly map to the FreeType flags FT_LOAD_DEFAULT, etc. The old synonyms (respectively "either", "native", "auto", and "none") are still supported. To get normalized values, use .backend_agg.get_hinting_flag, which returns integer flag values.