API Changes for 3.5.0

Behaviour changes

First argument to subplot_mosaic renamed

Both FigureBase.subplot_mosaic, and pyplot.subplot_mosaic have had the first positional argument renamed from layout to mosaic. As we have consolidated the constrained_layout and tight_layout keyword arguments in the Figure creation functions of pyplot into a single layout keyword argument, the original subplot_mosaic argument name would collide.

As this API is provisional, we are changing this argument name with no deprecation period.

Axes children are no longer separated by type

Formerly, axes.Axes children were separated by Artist type, into sublists such as Axes.lines. For methods that produced multiple elements (such as Axes.errorbar), though individual parts would have similar zorder, this separation might cause them to be drawn at different times, causing inconsistent results when overlapping other Artists.

Now, the children are no longer separated by type, and the sublist properties are generated dynamically when accessed. Consequently, Artists will now always appear in the correct sublist; e.g., if axes.Axes.add_line is called on a Patch, it will appear in the Axes.patches sublist, not Axes.lines. The Axes.add_* methods will now warn if passed an unexpected type.

Modification of the following sublists is still accepted, but deprecated:

  • Axes.artists

  • Axes.collections

  • Axes.images

  • Axes.lines

  • Axes.patches

  • Axes.tables

  • Axes.texts

To remove an Artist, use its Artist.remove method. To add an Artist, use the corresponding Axes.add_* method.

MatplotlibDeprecationWarning now subclasses DeprecationWarning

Historically, it has not been possible to filter MatplotlibDeprecationWarnings by checking for DeprecationWarning, since we subclass UserWarning directly.

The decision to not subclass DeprecationWarning has to do with a decision from core Python in the 2.x days to not show DeprecationWarnings to users. However, there is now a more sophisticated filter in place (see https://www.python.org/dev/peps/pep-0565/).

Users will now see MatplotlibDeprecationWarning only during interactive sessions, and these can be silenced by the standard mechanism:

warnings.filterwarnings("ignore", category=DeprecationWarning)

Library authors must now enable DeprecationWarnings explicitly in order for (non-interactive) CI/CD pipelines to report back these warnings, as is standard for the rest of the Python ecosystem:

warnings.filterwarnings("always", DeprecationWarning)

Artist.set applies artist properties in the order in which they are given

The change only affects the interaction between the color, edgecolor, facecolor, and (for Collections) alpha properties: the color property now needs to be passed first in order not to override the other properties. This is consistent with e.g. Artist.update, which did not reorder the properties passed to it.

pcolor(mesh) shading defaults to auto

The shading keyword argument for Axes.pcolormesh and Axes.pcolor default has been changed to 'auto'.

Passing Z(M, N), x(N), y(M) to pcolormesh with shading='flat' will now raise a TypeError. Use shading='auto' or shading='nearest' for x and y to be treated as cell centers, or drop the last column and row of Z to get the old behaviour with shading='flat'.

Colorbars now have pan and zoom functionality

Interactive plots with colorbars can now be zoomed and panned on the colorbar axis. This adjusts the vmin and vmax of the ScalarMappable associated with the colorbar. This is currently only enabled for continuous norms. Norms used with contourf and categoricals, such as BoundaryNorm and NoNorm, have the interactive capability disabled by default. cb.ax.set_navigate() can be used to set whether a colorbar axes is interactive or not.

Colorbar lines no longer clipped

If a colorbar has lines added to it (e.g. for contour lines), these will no longer be clipped. This is an improvement for lines on the edge of the colorbar, but could lead to lines off the colorbar if the limits of the colorbar are changed.

Figure.suppressComposite now also controls compositing of Axes images

The output of NonUniformImage and PcolorImage has changed

Pixel-level differences may be observed in images generated using NonUniformImage or PcolorImage, typically for pixels exactly at the boundary between two data cells (no user-facing axes method currently generates NonUniformImages, and only pcolorfast can generate PcolorImages). These artists are also now slower, normally by ~1.5x but sometimes more (in particular for NonUniformImage(interpolation="bilinear"). This slowdown arises from fixing occasional floating point inaccuracies.

Change of the (default) legend handler for Line2D instances

The default legend handler for Line2D instances (HandlerLine2D) now consistently exposes all the attributes and methods related to the line marker (#11358). This makes it easy to change the marker features after instantiating a legend.

import matplotlib.pyplot as plt

fig, ax = plt.subplots()

ax.plot([1, 3, 2], marker="s", label="Line", color="pink", mec="red", ms=8)
leg = ax.legend()

leg.legendHandles[0].set_color("lightgray")
leg.legendHandles[0].set_mec("black")  # marker edge color

The former legend handler for Line2D objects has been renamed HandlerLine2DCompound. To revert to the previous behaviour, one can use

import matplotlib.legend as mlegend
from matplotlib.legend_handler import HandlerLine2DCompound
from matplotlib.lines import Line2D

mlegend.Legend.update_default_handler_map({Line2D: HandlerLine2DCompound()})

Setting Line2D marker edge/face color to None use rcParams

Line2D.set_markeredgecolor(None) and Line2D.set_markerfacecolor(None) now set the line property using the corresponding rcParam (rcParams["lines.markeredgecolor"] (default: 'auto') and rcParams["lines.markerfacecolor"] (default: 'auto')). This is consistent with other Line2D property setters.

Default theta tick locations for wedge polar plots have changed

For polar plots that don't cover a full circle, the default theta tick locations are now at multiples of 10°, 15°, 30°, 45°, 90°, rather than using values that mostly make sense for linear plots (20°, 25°, etc.).

axvspan now plots full wedges in polar plots

... rather than triangles.

Convenience converter from Scale to Normalize now public

Downstream libraries can take advantage of colors.make_norm_from_scale to create a Normalize subclass directly from an existing scale. Usually norms have a scale, and the advantage of having a ScaleBase attached to a norm is to provide a scale, and associated tick locators and formatters, for the colorbar.

ContourSet always use PathCollection

In order to correct rendering issues with closed loops, the ContourSet now creates a PathCollection instead of a LineCollection for line contours. This type matches the artist used for filled contours.

This affects ContourSet itself and its subclasses, QuadContourSet (returned by Axes.contour), and TriContourSet (returned by Axes.tricontour).

hatch.SmallFilledCircles inherits from hatch.Circles

The hatch.SmallFilledCircles class now inherits from hatch.Circles rather than from hatch.SmallCircles.

hexbin with a log norm

hexbin no longer (incorrectly) adds 1 to every bin value if a log norm is being used.

Setting invalid rcParams["date.converter"] now raises ValueError

Previously, invalid values passed to rcParams["date.converter"] (default: 'auto') would be ignored with a UserWarning, but now raise ValueError.

Text and TextBox added parse_math option

Text and TextBox objects now allow a parse_math keyword-only argument which controls whether math should be parsed from the displayed string. If True, the string will be parsed as a math text object. If False, the string will be considered a literal and no parsing will occur.

For Text, this argument defaults to True. For TextBox this argument defaults to False.

Type1Font objects now decrypt the encrypted part

Type 1 fonts have a large part of their code encrypted as an obsolete copy-protection measure. This part is now available decrypted as the decrypted attribute of matplotlib.type1font.Type1Font. This decrypted data is not yet parsed, but this is a prerequisite for implementing subsetting.

3D contourf polygons placed between levels

The polygons used in a 3D contourf plot are now placed halfway between the contour levels, as each polygon represents the location of values that lie between two levels.

AxesDivider now defaults to rcParams-specified pads

AxesDivider.append_axes, AxesDivider.new_horizontal, and AxesDivider.new_vertical now default to paddings specified by rcParams["figure.subplot.wspace"] (default: 0.2) and rcParams["figure.subplot.hspace"] (default: 0.2) rather than zero.

Deprecations

Discouraged: Figure parameters tight_layout and constrained_layout

The Figure parameters tight_layout and constrained_layout are triggering competing layout mechanisms and thus should not be used together.

To make the API clearer, we've merged them under the new parameter layout with values 'constrained' (equal to constrained_layout=True), 'tight' (equal to tight_layout=True). If given, layout takes precedence.

The use of tight_layout and constrained_layout is discouraged in favor of layout. However, these parameters will stay available for backward compatibility.

Modification of Axes children sublists

See Axes children are no longer separated by type for more information; modification of the following sublists is deprecated:

  • Axes.artists

  • Axes.collections

  • Axes.images

  • Axes.lines

  • Axes.patches

  • Axes.tables

  • Axes.texts

To remove an Artist, use its Artist.remove method. To add an Artist, use the corresponding Axes.add_* method.

Passing incorrect types to Axes.add_* methods

The following Axes.add_* methods will now warn if passed an unexpected type. See their documentation for the types they expect.

Discouraged: plot_date

The use of plot_date is discouraged. This method exists for historic reasons and may be deprecated in the future.

  • datetime-like data should directly be plotted using plot.

  • If you need to plot plain numeric data as Matplotlib date format or need to set a timezone, call ax.xaxis.axis_date / ax.yaxis.axis_date before plot. See Axis.axis_date.

epoch2num and num2epoch are deprecated

These methods convert from unix timestamps to matplotlib floats, but are not used internally to matplotlib, and should not be needed by end users. To convert a unix timestamp to datetime, simply use datetime.datetime.utcfromtimestamp, or to use NumPy datetime64 dt = np.datetim64(e*1e6, 'us').

Auto-removal of grids by pcolor and pcolormesh

pcolor and pcolormesh currently remove any visible axes major grid. This behavior is deprecated; please explicitly call ax.grid(False) to remove the grid.

The first parameter of Axes.grid and Axis.grid has been renamed to visible

The parameter was previously named b. This deprecation only matters if that parameter was passed using a keyword argument, e.g. grid(b=False).

Unification and cleanup of Selector widget API

The API for Selector widgets has been unified to use:

  • props for the properties of the Artist representing the selection.

  • handle_props for the Artists representing handles for modifying the selection.

  • grab_range for the maximal tolerance to grab a handle with the mouse.

Additionally, several internal parameters and attribute have been deprecated with the intention of keeping them private.

RectangleSelector and EllipseSelector

The drawtype keyword argument to RectangleSelector is deprecated. In the future the only behaviour will be the default behaviour of drawtype='box'.

Support for drawtype=line will be removed altogether as it is not clear which points are within and outside a selector that is just a line. As a result, the lineprops keyword argument to RectangleSelector is also deprecated.

To retain the behaviour of drawtype='none', use rectprops={'visible': False} to make the drawn Rectangle invisible.

Cleaned up attributes and arguments are:

  • The active_handle attribute has been privatized and deprecated.

  • The drawtype attribute has been privatized and deprecated.

  • The eventpress attribute has been privatized and deprecated.

  • The eventrelease attribute has been privatized and deprecated.

  • The interactive attribute has been privatized and deprecated.

  • The marker_props argument is deprecated, use handle_props instead.

  • The maxdist argument is deprecated, use grab_range instead.

  • The rectprops argument is deprecated, use props instead.

  • The rectprops attribute has been privatized and deprecated.

  • The state attribute has been privatized and deprecated.

  • The to_draw attribute has been privatized and deprecated.

PolygonSelector

  • The line attribute is deprecated. If you want to change the selector artist properties, use the set_props or set_handle_props methods.

  • The lineprops argument is deprecated, use props instead.

  • The markerprops argument is deprecated, use handle_props instead.

  • The maxdist argument and attribute is deprecated, use grab_range instead.

  • The vertex_select_radius argument and attribute is deprecated, use grab_range instead.

SpanSelector

  • The active_handle attribute has been privatized and deprecated.

  • The eventpress attribute has been privatized and deprecated.

  • The eventrelease attribute has been privatized and deprecated.

  • The maxdist argument and attribute is deprecated, use grab_range instead.

  • The pressv attribute has been privatized and deprecated.

  • The prev attribute has been privatized and deprecated.

  • The rect attribute has been privatized and deprecated.

  • The rectprops argument is deprecated, use props instead.

  • The rectprops attribute has been privatized and deprecated.

  • The span_stays argument is deprecated, use the interactive argument instead.

  • The span_stays attribute has been privatized and deprecated.

  • The state attribute has been privatized and deprecated.

LassoSelector

  • The lineprops argument is deprecated, use props instead.

  • The onpress and onrelease methods are deprecated. They are straight aliases for press and release.

ConversionInterface.convert no longer needs to accept unitless values

Previously, custom subclasses of units.ConversionInterface needed to implement a convert method that not only accepted instances of the unit, but also unitless values (which are passed through as is). This is no longer the case (convert is never called with a unitless value), and such support in StrCategoryConverter is deprecated. Likewise, the ConversionInterface.is_numlike helper is deprecated.

Consider calling Axis.convert_units instead, which still supports unitless values.

Locator and Formatter wrapper methods

The set_view_interval, set_data_interval and set_bounds methods of Locators and Formatters (and their common base class, TickHelper) are deprecated. Directly manipulate the view and data intervals on the underlying axis instead.

Unused positional parameters to print_<fmt> methods

None of the print_<fmt> methods implemented by canvas subclasses used positional arguments other that the first (the output filename or file-like), so these extra parameters are deprecated.

QuadMesh signature

The QuadMesh signature

def __init__(meshWidth, meshHeight, coordinates,
             antialiased=True, shading='flat', **kwargs)

is deprecated and replaced by the new signature

def __init__(coordinates, *, antialiased=True, shading='flat', **kwargs)

In particular:

  • The coordinates argument must now be a (M, N, 2) array-like. Previously, the grid shape was separately specified as (meshHeight + 1, meshWidth + 1) and coordinates could be an array-like of any shape with M * N * 2 elements.

  • All parameters except coordinates are keyword-only now.

rcParams will no longer cast inputs to str

After a deprecation period, rcParams that expect a (non-pathlike) str will no longer cast non-str inputs using str. This will avoid confusing errors in subsequent code if e.g. a list input gets implicitly cast to a str.

Case-insensitive scales

Previously, scales could be set case-insensitively (e.g., set_xscale("LoG")). This is deprecated; all builtin scales use lowercase names.

Interactive cursor details

Setting a mouse cursor on a window has been moved from the toolbar to the canvas. Consequently, several implementation details on toolbars and within backends have been deprecated.

backend_tools.SetCursorBase and subclasses

backend_tools.SetCursorBase was subclassed to provide backend-specific implementations of set_cursor. As that is now deprecated, the subclassing is no longer necessary. Consequently, the following subclasses are also deprecated:

  • matplotlib.backends.backend_gtk3.SetCursorGTK3

  • matplotlib.backends.backend_qt5.SetCursorQt

  • matplotlib.backends._backend_tk.SetCursorTk

  • matplotlib.backends.backend_wx.SetCursorWx

Instead, use the backend_tools.ToolSetCursor class.

cursord in GTK, Qt, and wx backends

The backend_gtk3.cursord, backend_qt.cursord, and backend_wx.cursord dictionaries are deprecated. This makes the GTK module importable on headless environments.

Miscellaneous deprecations

  • is_url and URL_REGEX are deprecated. (They were previously defined in the toplevel matplotlib module.)

  • The ArrowStyle.beginarrow and ArrowStyle.endarrow attributes are deprecated; use the arrow attribute to define the desired heads and tails of the arrow.

  • backend_pgf.LatexManager.str_cache is deprecated.

  • backends.qt_compat.ETS and backends.qt_compat.QT_RC_MAJOR_VERSION are deprecated, with no replacement.

  • The blocking_input module has been deprecated. Instead, use canvas.start_event_loop() and canvas.stop_event_loop() while connecting event callbacks as needed.

  • cbook.report_memory is deprecated; use psutil.virtual_memory instead.

  • cm.LUTSIZE is deprecated. Use rcParams["image.lut"] (default: 256) instead. This value only affects colormap quantization levels for default colormaps generated at module import time.

  • Collection.__init__ previously ignored transOffset without offsets also being specified. In the future, transOffset will begin having an effect regardless of offsets. In the meantime, if you wish to set transOffset, call Collection.set_offset_transform explicitly.

  • Colorbar.patch is deprecated; this attribute is not correctly updated anymore.

  • ContourLabeler.get_label_width is deprecated.

  • dviread.PsfontsMap now raises LookupError instead of KeyError for missing fonts.

  • Dvi.baseline is deprecated (with no replacement).

  • The format parameter of dviread.find_tex_file is deprecated (with no replacement).

  • FancyArrowPatch.get_path_in_displaycoord and ConnectionPath.get_path_in_displaycoord are deprecated. The path in display coordinates can still be obtained, as for other patches, using patch.get_transform().transform_path(patch.get_path()).

  • The font_manager.win32InstalledFonts and font_manager.get_fontconfig_fonts helper functions have been deprecated.

  • All parameters of imshow starting from aspect will become keyword-only.

  • QuadMesh.convert_mesh_to_paths and QuadMesh.convert_mesh_to_triangles are deprecated. QuadMesh.get_paths() can be used as an alternative for the former; there is no replacement for the latter.

  • ScalarMappable.callbacksSM is deprecated. Use ScalarMappable.callbacks instead.

  • streamplot.get_integrator is deprecated.

  • style.core.STYLE_FILE_PATTERN, style.core.load_base_library, and style.core.iter_user_libraries are deprecated.

  • SubplotParams.validate is deprecated. Use SubplotParams.update to change SubplotParams while always keeping it in a valid state.

  • The grey_arrayd, font_family, font_families, and font_info attributes of TexManager are deprecated.

  • Text.get_prop_tup is deprecated with no replacements (because the Text class cannot know whether a backend needs to update cache e.g. when the text's color changes).

  • Tick.apply_tickdir didn't actually update the tick markers on the existing Line2D objects used to draw the ticks and is deprecated; use Axis.set_tick_params instead.

  • tight_layout.auto_adjust_subplotpars is deprecated.

  • The grid_info attribute of axisartist classes has been deprecated.

  • axisartist.clip_path is deprecated with no replacement.

  • axes_grid1.axes_grid.CbarAxes and axes_grid1.axisartist.CbarAxes are deprecated (they are now dynamically generated based on the owning axes class).

  • The axes_grid1.Divider.get_vsize_hsize and axes_grid1.Grid.get_vsize_hsize methods are deprecated. Copy their implementations if needed.

  • AxesDivider.append_axes(..., add_to_figure=False) is deprecated. Use ax.remove() to remove the Axes from the figure if needed.

  • FixedAxisArtistHelper.change_tick_coord is deprecated with no replacement.

  • floating_axes.GridHelperCurveLinear.get_boundary is deprecated, with no replacement.

  • ParasiteAxesBase.get_images_artists has been deprecated.

  • The "units finalize" signal (previously emitted by Axis instances) is deprecated. Connect to "units" instead.

  • Passing formatting parameters positionally to stem() is deprecated

plot_directive deprecations

The :encoding: option to .. plot directive has had no effect since Matplotlib 1.3.1, and is now deprecated.

The following helpers in matplotlib.sphinxext.plot_directive are deprecated:

Testing support

matplotlib.test() is deprecated

Run tests using pytest from the commandline instead. The variable matplotlib.default_test_modules is only used for matplotlib.test() and is thus deprecated as well.

To test an installed copy, be sure to specify both matplotlib and mpl_toolkits with --pyargs:

python -m pytest --pyargs matplotlib.tests mpl_toolkits.tests

See Testing for more details.

Unused pytest fixtures and markers

The fixture matplotlib.testing.conftest.mpl_image_comparison_parameters is not used internally by Matplotlib. If you use this please copy it into your code base.

The @pytest.mark.style marker is deprecated; use @mpl.style.context, which has the same effect.

Support for nx1 = None or ny1 = None in AxesLocator and Divider.locate

In axes_grid1.axes_divider, various internal APIs will stop supporting passing nx1 = None or ny1 = None to mean nx + 1 or ny + 1, in preparation for a possible future API which allows indexing and slicing of dividers (possibly divider[a:b] == divider.new_locator(a, b), but also divider[a:] == divider.new_locator(a, <end>)). The user-facing Divider.new_locator API is unaffected -- it correctly normalizes nx1 = None and ny1 = None as needed.

Removals

The following deprecated APIs have been removed:

Removed behaviour

Stricter validation of function parameters

  • Calling Figure.add_axes with no arguments will raise an error. Adding a free-floating axes needs a position rectangle. If you want a figure-filling single axes, use Figure.add_subplot instead.

  • Figure.add_subplot validates its inputs; in particular, for add_subplot(rows, cols, index), all parameters must be integral. Previously strings and floats were accepted and converted to int.

  • Passing None as the which argument to autofmt_xdate is no longer supported; use its more explicit synonym, which="major", instead.

  • Setting the orientation of an eventplot() or EventCollection to "none" or None is no longer supported; set it to "horizontal" instead. Moreover, the two orientations ("horizontal" and "vertical") are now case-sensitive.

  • Passing parameters norm and vmin/vmax simultaneously to functions using colormapping such as scatter() and imshow() is no longer supported. Instead of norm=LogNorm(), vmin=min_val, vmax=max_val pass norm=LogNorm(min_val, max_val). vmin and vmax should only be used without setting norm.

  • Passing None as either the radius or startangle arguments of an Axes.pie is no longer accepted; use the explicit defaults of 1 and 0, respectively, instead.

  • Passing None as the normalize argument of Axes.pie (the former default) is no longer accepted, and the pie will always be normalized by default. If you wish to plot an incomplete pie, explicitly pass normalize=False.

  • Support for passing None to subplot_class_factory has been removed. Explicitly pass in the base Axes class instead.

  • Passing multiple keys as a single comma-separated string or multiple arguments to ToolManager.update_keymap is no longer supported; pass keys as a list of strings instead.

  • Passing the dash offset as None is no longer accepted, as this was never universally implemented, e.g. for vector output. Set the offset to 0 instead.

  • Setting a custom method overriding Artist.contains using Artist.set_contains has been removed, as has Artist.get_contains. There is no replacement, but you may still customize pick events using Artist.set_picker.

  • semilogx, semilogy, loglog, LogScale, and SymmetricalLogScale used to take keyword arguments that depends on the axis orientation ("basex" vs "basey", "subsx" vs "subsy", "nonposx" vs "nonposy"); these parameter names have been removed in favor of "base", "subs", "nonpositive". This removal also affects e.g. ax.set_yscale("log", basey=...) which must now be spelled ax.set_yscale("log", base=...).

    The change from "nonpos" to "nonpositive" also affects LogTransform, InvertedLogTransform, SymmetricalLogTransform, etc.

    To use different bases for the x-axis and y-axis of a loglog plot, use e.g. ax.set_xscale("log", base=10); ax.set_yscale("log", base=2).

  • Passing None, or no argument, to parasite_axes_class_factory, parasite_axes_auxtrans_class_factory, host_axes_class_factory is no longer accepted; pass an explicit base class instead.

Case-sensitivity is now enforced more

  • Upper or mixed-case property names are no longer normalized to lowercase in Artist.set and Artist.update. This allows one to pass names such as patchA or UVC.

  • Case-insensitive capstyles and joinstyles are no longer lower-cased; please pass capstyles ("miter", "round", "bevel") and joinstyles ("butt", "round", "projecting") as lowercase.

  • Saving metadata in PDF with the PGF backend no longer changes keys to lowercase. Only the canonically cased keys listed in the PDF specification (and the PdfPages documentation) are accepted.

No implicit initialization of Tick attributes

The Tick constructor no longer initializes the attributes tick1line, tick2line, gridline, label1, and label2 via _get_tick1line, _get_tick2line, _get_gridline, _get_text1, and _get_text2. Please directly set the attribute in the subclass' __init__ instead.

Removal of old file mode flag

Flags containing "U" passed to cbook.to_filehandle and cbook.open_file_cm are no longer accepted. This is consistent with their removal from open in Python 3.9.

Keymaps toggling Axes.get_navigate have been removed

This includes numeric key events and rcParams.

The TTFPATH and AFMPATH environment variables

Support for the (undocumented) TTFPATH and AFMPATH environment variables has been removed. Register additional fonts using matplotlib.font_manager.fontManager.addfont().

Modules

  • matplotlib.backends.qt_editor.formsubplottool; use matplotlib.backends.backend_qt.SubplotToolQt instead.

  • matplotlib.compat

  • matplotlib.ttconv

  • The Qt4-based backends, qt4agg and qt4cairo, have been removed. Qt4 has reached its end-of-life in 2015 and there are no releases of either PyQt4 or PySide for recent versions of Python. Please use one of the Qt5 or Qt6 backends.

Classes, methods and attributes

The following module-level classes/variables have been removed:

  • backend_bases.StatusbarBase and all its subclasses, and StatusBarWx; messages are displayed in the toolbar

  • backend_pgf.GraphicsContextPgf

  • MODIFIER_KEYS, SUPER, ALT, CTRL, and SHIFT of matplotlib.backends.backend_qt5agg and matplotlib.backends.backend_qt5cairo

  • backend_wx.DEBUG_MSG

  • dviread.Encoding

  • Fil, Fill, Filll, NegFil, NegFill, NegFilll, and SsGlue from mathtext; directly construct glue instances with Glue("fil"), etc.

  • mathtext.GlueSpec

  • OldScalarFormatter, IndexFormatter and IndexDateFormatter; use FuncFormatter instead

  • OldAutoLocator

  • AVConvBase, AVConvWriter and AVConvFileWriter. Debian 8 (2015, EOL 06/2020) and Ubuntu 14.04 (EOL 04/2019) were the last versions of Debian and Ubuntu to ship avconv. It remains possible to force the use of avconv by using the FFmpeg-based writers with rcParams["animation.ffmpeg_path"] (default: 'ffmpeg') set to "avconv".

  • matplotlib.axes._subplots._subplot_classes

  • axes_grid1.axes_rgb.RGBAxesBase; use RGBAxes instead

The following class attributes have been removed:

  • backend_pgf.LatexManager.latex_stdin_utf8

  • backend_pgf.PdfPages.metadata

  • ContourSet.ax and Quiver.ax; use ContourSet.axes or Quiver.axes as with other artists

  • DateFormatter.illegal_s

  • dates.YearLocator.replaced; YearLocator is now a subclass of RRuleLocator, and the attribute YearLocator.replaced has been removed. For tick locations that required modifying this, a custom rrule and RRuleLocator can be used instead.

  • FigureManagerBase.statusbar; messages are displayed in the toolbar

  • FileMovieWriter.clear_temp

  • mathtext.Glue.glue_subtype

  • MovieWriter.args_key, MovieWriter.exec_key, and HTMLWriter.args_key

  • NavigationToolbar2QT.basedir; the base directory to the icons is os.path.join(mpl.get_data_path(), "images")

  • NavigationToolbar2QT.ctx

  • NavigationToolbar2QT.parent; to access the parent window, use toolbar.canvas.parent() or toolbar.parent()

  • prevZoomRect, retinaFix, savedRetinaImage, wxoverlay, zoomAxes, zoomStartX, and zoomStartY attributes of NavigationToolbar2Wx

  • NonUniformImage.is_grayscale, PcolorImage.is_grayscale, for consistency with AxesImage.is_grayscale. (Note that previously, these attributes were only available after rendering the image).

  • RendererCairo.fontweights, RendererCairo.fontangles

  • used_characters of RendererPdf, PdfFile, and RendererPS

  • LogScale.LogTransform, LogScale.InvertedLogTransform, SymmetricalScale.SymmetricalTransform, and SymmetricalScale.InvertedSymmetricalTransform; directly access the transform classes from matplotlib.scale

  • cachedir, rgba_arrayd, serif, sans_serif, cursive, and monospace attributes of TexManager

  • axleft, axright, axbottom, axtop, axwspace, and axhspace attributes of widgets.SubplotTool; access the ax attribute of the corresponding slider

  • widgets.TextBox.params_to_disable

  • angle_helper.LocatorBase.den; it has been renamed to nbins

  • axes_grid.CbarAxesBase.cbid and axes_grid.CbarAxesBase.locator; use mappable.colorbar_cid or colorbar.locator instead

The following class methods have been removed:

  • Axes.update_datalim_bounds; use ax.dataLim.set(Bbox.union([ax.dataLim, bounds]))

  • pan and zoom methods of Axis and Locator have been removed; panning and zooming are now implemented using the start_pan, drag_pan, and end_pan methods of Axes

  • .BboxBase.inverse_transformed; call BboxBase.transformed on the inverted() transform

  • Collection.set_offset_position and Collection.get_offset_position have been removed; the offset_position of the Collection class is now "screen"

  • Colorbar.on_mappable_changed and Colorbar.update_bruteforce; use Colorbar.update_normal() instead

  • docstring.Substitution.from_params has been removed; directly assign to params of Substitution instead

  • DraggableBase.artist_picker; set the artist's picker instead

  • DraggableBase.on_motion_blit; use DraggableBase.on_motion instead

  • FigureCanvasGTK3._renderer_init

  • Locator.refresh() and the associated helper methods NavigationToolbar2.draw() and ToolViewsPositions.refresh_locators()

  • track_characters and merge_used_characters of RendererPdf, PdfFile, and RendererPS

  • RendererWx.get_gc

  • SubplotSpec.get_rows_columns; use the GridSpec.nrows, GridSpec.ncols, SubplotSpec.rowspan, and SubplotSpec.colspan properties instead.

  • ScalarMappable.update_dict, ScalarMappable.add_checker(), and ScalarMappable.check_update(); register a callback in ScalarMappable.callbacks to be notified of updates

  • TexManager.make_tex_preview and TexManager.make_dvi_preview

  • funcleft, funcright, funcbottom, functop, funcwspace, and funchspace methods of widgets.SubplotTool

  • axes_grid1.axes_rgb.RGBAxes.add_RGB_to_figure

  • axisartist.axis_artist.AxisArtist.dpi_transform

  • axisartist.grid_finder.MaxNLocator.set_factor and axisartist.grid_finder.FixedLocator.set_factor; the factor is always 1 now

Functions

  • bezier.make_path_regular has been removed; use Path.cleaned() (or Path.cleaned(curves=True), etc.) instead, but note that these methods add a STOP code at the end of the path.

  • bezier.concatenate_paths has been removed; use Path.make_compound_path() instead.

  • cbook.local_over_kwdict has been removed; use cbook.normalize_kwargs instead.

  • qt_compat.is_pyqt5 has been removed due to the release of PyQt6. The Qt version can be checked using QtCore.qVersion().

  • testing.compare.make_external_conversion_command has been removed.

  • axes_grid1.axes_rgb.imshow_rgb has been removed; use imshow(np.dstack([r, g, b])) instead.

Arguments

  • The s parameter to Axes.annotate and pyplot.annotate is no longer supported; use the new name text.

  • The inframe parameter to Axes.draw has been removed; use Axes.redraw_in_frame instead.

  • The required, forbidden and allowed parameters of cbook.normalize_kwargs have been removed.

  • The ismath parameter of the draw_tex method of all renderer classes has been removed (as a call to draw_tex — not to be confused with draw_text! — means that the entire string should be passed to the usetex machinery anyways). Likewise, the text machinery will no longer pass the ismath parameter when calling draw_tex (this should only matter for backend implementers).

  • The quality, optimize, and progressive parameters of Figure.savefig (which only affected JPEG output) have been removed, as well as from the corresponding print_jpg methods. JPEG output options can be set by directly passing the relevant parameters in pil_kwargs.

  • The clear_temp parameter of FileMovieWriter has been removed; files placed in a temporary directory (using frame_prefix=None, the default) will be cleared; files placed elsewhere will not.

  • The copy parameter of mathtext.Glue has been removed.

  • The quantize parameter of Path.cleaned() has been removed.

  • The dummy parameter of RendererPgf has been removed.

  • The props parameter of Shadow has been removed; use keyword arguments instead.

  • The recursionlimit parameter of matplotlib.test has been removed.

  • The label parameter of Tick has no effect and has been removed.

  • MaxNLocator no longer accepts a positional parameter and the keyword argument nbins simultaneously because they specify the same quantity.

  • The add_all parameter to axes_grid.Grid, axes_grid.ImageGrid, axes_rgb.make_rgb_axes, and axes_rgb.RGBAxes have been removed; the APIs always behave as if add_all=True.

  • The den parameter of axisartist.angle_helper.LocatorBase has been removed; use nbins instead.

  • The s keyword argument to AnnotationBbox.get_fontsize has no effect and has been removed.

  • The offset_position keyword argument of the Collection class has been removed; the offset_position now "screen".

  • Arbitrary keyword arguments to StreamplotSet have no effect and have been removed.

  • The fontdict and minor parameters of Axes.set_xticklabels / Axes.set_yticklabels are now keyword-only.

  • All parameters of Figure.subplots except nrows and ncols are now keyword-only; this avoids typing e.g. subplots(1, 1, 1) when meaning subplot(1, 1, 1), but actually getting subplots(1, 1, sharex=1).

  • All parameters of pyplot.tight_layout are now keyword-only, to be consistent with Figure.tight_layout.

  • ColorbarBase only takes a single positional argument now, the Axes to create it in, with all other options required to be keyword arguments. The warning for keyword arguments that were overridden by the mappable is now removed.

  • Omitting the renderer parameter to Axes.draw is no longer supported; use axes.draw_artist(axes) instead.

  • Passing ismath="TeX!" to RendererAgg.get_text_width_height_descent is no longer supported; pass ismath="TeX" instead,

  • Changes to the signature of the Axes.draw method make it consistent with all other artists; thus additional parameters to Artist.draw have also been removed.

rcParams

  • The animation.avconv_path and animation.avconv_args rcParams have been removed.

  • The animation.html_args rcParam has been removed.

  • The keymap.all_axes rcParam has been removed.

  • The mathtext.fallback_to_cm rcParam has been removed. Use rcParams["mathtext.fallback"] (default: 'cm') instead.

  • The savefig.jpeg_quality rcParam has been removed.

  • The text.latex.preview rcParam has been removed.

  • The following deprecated rcParams validators, defined in rcsetup, have been removed:

    • validate_alignment

    • validate_axes_titlelocation

    • validate_axis_locator

    • validate_bool_maybe_none

    • validate_fontset

    • validate_grid_axis

    • validate_hinting

    • validate_legend_loc

    • validate_mathtext_default

    • validate_movie_frame_fmt

    • validate_movie_html_fmt

    • validate_movie_writer

    • validate_nseq_float

    • validate_nseq_int

    • validate_orientation

    • validate_pgf_texsystem

    • validate_ps_papersize

    • validate_svg_fontset

    • validate_toolbar

    • validate_webagg_address

  • Some rcParam validation has become stricter:

Development changes

Increase to minimum supported versions of dependencies

For Matplotlib 3.5, the minimum supported versions and some optional dependencies are being bumped:

Dependency

min in mpl3.4

min in mpl3.5

NumPy

1.16

1.17

Tk (optional)

8.3

8.4

This is consistent with our Minimum version of dependencies policy and NEP29

New wheel architectures

Wheels have been added for:

  • Python 3.10

  • PyPy 3.7

  • macOS on Apple Silicon (both arm64 and universal2)

New build dependencies

Versioning has been switched from bundled versioneer to setuptools-scm using the release-branch-semver version scheme. The latter is well-maintained, but may require slight modification to packaging scripts.

The setuptools-scm-git-archive plugin is also used for consistent version export.

Data directory is no longer optional

Historically, the mpl-data directory has been optional (example files were unnecessary, and fonts could be deleted if a suitable dependency on a system font were provided). Though example files are still optional, they have been substantially pared down, and we now consider the directory to be required.

Specifically, the matplotlibrc file found there is used for runtime verifications and must exist. Packagers may still symlink fonts to system versions if needed.

New runtime dependencies

fontTools for type 42 subsetting

A new dependency fontTools is integrated into Matplotlib 3.5. It is designed to be used with PS/EPS and PDF documents; and handles Type 42 font subsetting.

Underscore support in LaTeX

The underscore package is now a requirement to improve support for underscores in LaTeX.

This is consistent with our Minimum version of dependencies policy.

Matplotlib-specific build options moved from setup.cfg to mplsetup.cfg

In order to avoid conflicting with the use of setup.cfg by setuptools, the Matplotlib-specific build options have moved from setup.cfg to mplsetup.cfg. The setup.cfg.template has been correspondingly been renamed to mplsetup.cfg.template.

Note that the path to this configuration file can still be set via the MPLSETUPCFG environment variable, which allows one to keep using the same file before and after this change.