Merge pull request matplotlib#30005 from dstansby/remove-get-cmap

Remove cm.get_cmap

Author: story645

doc/api/next_api_changes/removals/30005-DS.rst

@@ -0,0 +1,11 @@
+``matplotlib.cm.get_cmap``
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Colormaps are now available through the `.ColormapRegistry` accessible via
+`matplotlib.colormaps` or `matplotlib.pyplot.colormaps`.
+
+If you have the name of a colormap as a string, you can use a direct lookup,
+``matplotlib.colormaps[name]`` or ``matplotlib.pyplot.colormaps[name]``  . Alternatively, ``matplotlib.colormaps.get_cmap`` will
+maintain the existing behavior of additionally passing through `.Colormap` instances
+and converting ``None`` to the default colormap. `matplotlib.pyplot.get_cmap` will stay as a
+shortcut to ``matplotlib.colormaps.get_cmap``.

lib/matplotlib/cm.py

@@ -243,43 +243,6 @@ def get_cmap(self, cmap):
 _bivar_colormaps = ColormapRegistry(bivar_cmaps)
 
 
-# This is an exact copy of pyplot.get_cmap(). It was removed in 3.9, but apparently
-# caused more user trouble than expected. Re-added for 3.9.1 and extended the
-# deprecation period for two additional minor releases.
-@_api.deprecated(
-    '3.7',
-    removal='3.11',
-    alternative="``matplotlib.colormaps[name]`` or ``matplotlib.colormaps.get_cmap()``"
-                " or ``pyplot.get_cmap()``"
-    )
-def get_cmap(name=None, lut=None):
-    """
-    Get a colormap instance, defaulting to rc values if *name* is None.
-
-    Parameters
-    ----------
-    name : `~matplotlib.colors.Colormap` or str or None, default: None
-        If a `.Colormap` instance, it will be returned. Otherwise, the name of
-        a colormap known to Matplotlib, which will be resampled by *lut*. The
-        default, None, means :rc:`image.cmap`.
-    lut : int or None, default: None
-        If *name* is not already a Colormap instance and *lut* is not None, the
-        colormap will be resampled to have *lut* entries in the lookup table.
-
-    Returns
-    -------
-    Colormap
-    """
-    name = mpl._val_or_rc(name, 'image.cmap')
-    if isinstance(name, colors.Colormap):
-        return name
-    _api.check_in_list(sorted(_colormaps), name=name)
-    if lut is None:
-        return _colormaps[name]
-    else:
-        return _colormaps[name].resampled(lut)
-
-
 def _ensure_cmap(cmap):
     """
     Ensure that we have a `.Colormap` object.

lib/matplotlib/cm.pyi

@@ -19,6 +19,4 @@ _colormaps: ColormapRegistry = ...
 _multivar_colormaps: ColormapRegistry = ...
 _bivar_colormaps: ColormapRegistry = ...
 
-def get_cmap(name: str | colors.Colormap | None = ..., lut: int | None = ...) -> colors.Colormap: ...
-
 ScalarMappable = _ScalarMappable