matplotlib · QuLogic · Feb 5, 2026 · Feb 5, 2026
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -748,7 +748,7 @@ def __setitem__(self, key, val):
                 and val is rcsetup._auto_backend_sentinel
                 and "backend" in self):
             return
-        valid_key = _api.check_getitem(
+        valid_key = _api.getitem_checked(
             self.validate, rcParam=key, _error_cls=KeyError
         )
         try:

diff --git a/lib/matplotlib/_api/__init__.py b/lib/matplotlib/_api/__init__.py
@@ -189,7 +189,7 @@ def check_shape(shape, /, **kwargs):
             )
 
 
-def check_getitem(mapping, /, _error_cls=ValueError, **kwargs):
+def getitem_checked(mapping, /, _error_cls=ValueError, **kwargs):
     """
     *kwargs* must consist of a single *key, value* pair.  If *key* is in
     *mapping*, return ``mapping[value]``; else, raise an appropriate
@@ -202,10 +202,10 @@ def check_getitem(mapping, /, _error_cls=ValueError, **kwargs):
 
     Examples
     --------
-    >>> _api.check_getitem({"foo": "bar"}, arg=arg)
+    >>> _api.getitem_checked({"foo": "bar"}, arg=arg)
     """
     if len(kwargs) != 1:
-        raise ValueError("check_getitem takes a single keyword argument")
+        raise ValueError("getitem_checked takes a single keyword argument")
     (k, v), = kwargs.items()
     try:
         return mapping[v]

diff --git a/lib/matplotlib/_api/__init__.pyi b/lib/matplotlib/_api/__init__.pyi
@@ -42,7 +42,7 @@ def check_in_list(
     values: Sequence[Any], /, *, _print_supported_values: bool = ..., **kwargs: Any
 ) -> None: ...
 def check_shape(shape: tuple[int | None, ...], /, **kwargs: NDArray) -> None: ...
-def check_getitem(
+def getitem_checked(
         mapping: Mapping[Any, _T], /, _error_cls: type[Exception], **kwargs: Any
 ) -> _T: ...
 def caching_module_getattr(cls: type) -> Callable[[str], Any]: ...

diff --git a/lib/matplotlib/_type1font.py b/lib/matplotlib/_type1font.py
@@ -458,7 +458,7 @@ def _decrypt(ciphertext, key, ndiscard=4):
         That number of bytes is discarded from the beginning of plaintext.
         """
 
-        key = _api.check_getitem({'eexec': 55665, 'charstring': 4330}, key=key)
+        key = _api.getitem_checked({'eexec': 55665, 'charstring': 4330}, key=key)
         plaintext = []
         for byte in ciphertext:
             plaintext.append(byte ^ (key >> 8))
@@ -483,7 +483,7 @@ def _encrypt(plaintext, key, ndiscard=4):
         cryptanalysis.
         """
 
-        key = _api.check_getitem({'eexec': 55665, 'charstring': 4330}, key=key)
+        key = _api.getitem_checked({'eexec': 55665, 'charstring': 4330}, key=key)
         ciphertext = []
         for byte in b'\0' * ndiscard + plaintext:
             c = byte ^ (key >> 8)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -132,7 +132,7 @@ def get_title(self, loc="center"):
         titles = {'left': self._left_title,
                   'center': self.title,
                   'right': self._right_title}
-        title = _api.check_getitem(titles, loc=loc.lower())
+        title = _api.getitem_checked(titles, loc=loc.lower())
         return title.get_text()
 
     def set_title(self, label, fontdict=None, loc=None, pad=None, *, y=None,
@@ -199,7 +199,7 @@ def set_title(self, label, fontdict=None, loc=None, pad=None, *, y=None,
         titles = {'left': self._left_title,
                   'center': self.title,
                   'right': self._right_title}
-        title = _api.check_getitem(titles, loc=loc)
+        title = _api.getitem_checked(titles, loc=loc)
         default = {
             'fontsize': mpl.rcParams['axes.titlesize'],
             'fontweight': mpl.rcParams['axes.titleweight'],
@@ -8275,7 +8275,7 @@ def magnitude_spectrum(self, x, Fs=None, Fc=None, window=None,
                                               pad_to=pad_to, sides=sides)
         freqs += Fc
 
-        yunits = _api.check_getitem(
+        yunits = _api.getitem_checked(
             {None: 'energy', 'default': 'energy', 'linear': 'energy',
              'dB': 'dB'},
             scale=scale)

diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -904,7 +904,7 @@ def _request_autoscale_view(self, axis="all", tight=None):
             Either an element of ``self._axis_names``, or "all".
         tight : bool or None, default: None
         """
-        axis_names = _api.check_getitem(
+        axis_names = _api.getitem_checked(
             {**{k: [k] for k in self._axis_names}, "all": self._axis_names},
             axis=axis)
         for name in axis_names:
@@ -3426,10 +3426,10 @@ def ticklabel_format(self, *, axis='both', style=None, scilimits=None,
                                  ) from err
         STYLES = {'sci': True, 'scientific': True, 'plain': False, '': None, None: None}
         # The '' option is included for backwards-compatibility.
-        is_sci_style = _api.check_getitem(STYLES, style=style)
+        is_sci_style = _api.getitem_checked(STYLES, style=style)
         axis_map = {**{k: [v] for k, v in self._axis_map.items()},
                     'both': list(self._axis_map.values())}
-        axises = _api.check_getitem(axis_map, axis=axis)
+        axises = _api.getitem_checked(axis_map, axis=axis)
         try:
             for axis in axises:
                 if is_sci_style is not None:

diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -2451,7 +2451,7 @@ def set_label_position(self, position):
         ----------
         position : {'top', 'bottom'}
         """
-        self.label.set_verticalalignment(_api.check_getitem({
+        self.label.set_verticalalignment(_api.getitem_checked({
             'top': 'baseline', 'bottom': 'top',
         }, position=position))
         self.label_position = position
@@ -2678,7 +2678,7 @@ def set_label_position(self, position):
         position : {'left', 'right'}
         """
         self.label.set_rotation_mode('anchor')
-        self.label.set_verticalalignment(_api.check_getitem({
+        self.label.set_verticalalignment(_api.getitem_checked({
             'left': 'bottom', 'right': 'top',
         }, position=position))
         self.label_position = position
@@ -2733,7 +2733,7 @@ def set_offset_position(self, position):
         position : {'left', 'right'}
         """
         x, y = self.offsetText.get_position()
-        x = _api.check_getitem({'left': 0, 'right': 1}, position=position)
+        x = _api.getitem_checked({'left': 0, 'right': 1}, position=position)
 
         self.offsetText.set_ha(position)
         self.offsetText.set_position((x, y))

diff --git a/lib/matplotlib/backends/_backend_gtk.py b/lib/matplotlib/backends/_backend_gtk.py
@@ -67,7 +67,7 @@ def _create_application():
 
 
 def mpl_to_gtk_cursor_name(mpl_cursor):
-    return _api.check_getitem({
+    return _api.getitem_checked({
         Cursors.MOVE: "move",
         Cursors.HAND: "pointer",
         Cursors.POINTER: "default",

diff --git a/lib/matplotlib/backends/backend_cairo.py b/lib/matplotlib/backends/backend_cairo.py
@@ -342,7 +342,7 @@ def get_antialiased(self):
         return self.ctx.get_antialias()
 
     def set_capstyle(self, cs):
-        self.ctx.set_line_cap(_api.check_getitem(self._capd, capstyle=cs))
+        self.ctx.set_line_cap(_api.getitem_checked(self._capd, capstyle=cs))
         self._capstyle = cs
 
     def set_clip_rectangle(self, rectangle):
@@ -385,7 +385,7 @@ def get_rgb(self):
         return self.ctx.get_source().get_rgba()[:3]
 
     def set_joinstyle(self, js):
-        self.ctx.set_line_join(_api.check_getitem(self._joind, joinstyle=js))
+        self.ctx.set_line_join(_api.getitem_checked(self._joind, joinstyle=js))
         self._joinstyle = js
 
     def set_linewidth(self, w):

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -989,7 +989,7 @@ def _print_ps(
         papertype = papertype.lower()
         _api.check_in_list(['figure', *papersize], papertype=papertype)
 
-        orientation = _api.check_getitem(
+        orientation = _api.getitem_checked(
             _Orientation, orientation=orientation.lower())
 
         printer = (self._print_figure_tex

diff --git a/lib/matplotlib/backends/backend_qt.py b/lib/matplotlib/backends/backend_qt.py
@@ -281,7 +281,7 @@ def showEvent(self, event):
 
     def set_cursor(self, cursor):
         # docstring inherited
-        self.setCursor(_api.check_getitem(cursord, cursor=cursor))
+        self.setCursor(_api.getitem_checked(cursord, cursor=cursor))
 
     def mouseEventCoords(self, pos=None):
         """

diff --git a/lib/matplotlib/backends/backend_webagg_core.py b/lib/matplotlib/backends/backend_webagg_core.py
@@ -202,7 +202,7 @@ def draw_idle(self):
 
     def set_cursor(self, cursor):
         # docstring inherited
-        cursor = _api.check_getitem({
+        cursor = _api.getitem_checked({
             backend_tools.Cursors.HAND: 'pointer',
             backend_tools.Cursors.POINTER: 'default',
             backend_tools.Cursors.SELECT_REGION: 'crosshair',

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -768,7 +768,7 @@ def _on_key_up(self, event):
 
     def set_cursor(self, cursor):
         # docstring inherited
-        cursor = wx.Cursor(_api.check_getitem({
+        cursor = wx.Cursor(_api.getitem_checked({
             cursors.MOVE: wx.CURSOR_HAND,
             cursors.HAND: wx.CURSOR_HAND,
             cursors.POINTER: wx.CURSOR_ARROW,

diff --git a/lib/matplotlib/cm.py b/lib/matplotlib/cm.py
@@ -92,7 +92,7 @@ def __init__(self, cmaps):
         self._builtin_cmaps = tuple(cmaps)
 
     def __getitem__(self, item):
-        cmap = _api.check_getitem(self._cmaps, colormap=item, _error_cls=KeyError)
+        cmap = _api.getitem_checked(self._cmaps, colormap=item, _error_cls=KeyError)
         return cmap.copy()
 
     def __iter__(self):

diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
@@ -2004,7 +2004,7 @@ def set_orientation(self, orientation):
         ----------
         orientation : {'horizontal', 'vertical'}
         """
-        is_horizontal = _api.check_getitem(
+        is_horizontal = _api.getitem_checked(
             {"horizontal": True, "vertical": False},
             orientation=orientation)
         if is_horizontal == self.is_horizontal():

diff --git a/lib/matplotlib/colorbar.py b/lib/matplotlib/colorbar.py
@@ -349,7 +349,7 @@ def __init__(
         self.values = values
         self.boundaries = boundaries
         self.extend = extend
-        self._inside = _api.check_getitem(
+        self._inside = _api.getitem_checked(
             {'neither': slice(0, None), 'both': slice(1, -1),
              'min': slice(1, None), 'max': slice(0, -1)},
             extend=extend)
@@ -1340,7 +1340,7 @@ def drag_pan(self, button, key, x, y):
 def _normalize_location_orientation(location, orientation):
     if location is None:
         location = _get_ticklocation_from_orientation(orientation)
-    loc_settings = _api.check_getitem({
+    loc_settings = _api.getitem_checked({
         "left":   {"location": "left", "anchor": (1.0, 0.5),
                    "panchor": (0.0, 0.5), "pad": 0.10},
         "right":  {"location": "right", "anchor": (0.0, 0.5),
@@ -1358,13 +1358,13 @@ def _normalize_location_orientation(location, orientation):
 
 
 def _get_orientation_from_location(location):
-    return _api.check_getitem(
+    return _api.getitem_checked(
         {None: None, "left": "vertical", "right": "vertical",
          "top": "horizontal", "bottom": "horizontal"}, location=location)
 
 
 def _get_ticklocation_from_orientation(orientation):
-    return _api.check_getitem(
+    return _api.getitem_checked(
         {None: "right", "vertical": "right", "horizontal": "bottom"},
         orientation=orientation)
 

diff --git a/lib/matplotlib/colorizer.py b/lib/matplotlib/colorizer.py
@@ -763,7 +763,7 @@ def _ensure_norm(norm, n_components=1):
         if norm is None:
             norm = colors.Normalize()
         elif isinstance(norm, str):
-            scale_cls = _api.check_getitem(scale._scale_mapping, norm=norm)
+            scale_cls = _api.getitem_checked(scale._scale_mapping, norm=norm)
             return _auto_norm_from_scale(scale_cls)()
         return norm
     elif n_components > 1:

diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -3371,7 +3371,7 @@ def __init__(self, norms, vmin=None, vmax=None, clip=None):
 
         def resolve(norm):
             if isinstance(norm, str):
-                scale_cls = _api.check_getitem(scale._scale_mapping, norm=norm)
+                scale_cls = _api.getitem_checked(scale._scale_mapping, norm=norm)
                 return mpl.colorizer._auto_norm_from_scale(scale_cls)()
             elif isinstance(norm, Normalize):
                 return norm

diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -689,7 +689,7 @@ def set_loc(self, loc=None):
                         locs = locs[::-1]
                     loc = locs[0] + ' ' + locs[1]
             # check that loc is in acceptable strings
-            loc = _api.check_getitem(self.codes, loc=loc)
+            loc = _api.getitem_checked(self.codes, loc=loc)
         elif np.iterable(loc):
             # coerce iterable into tuple
             loc = tuple(loc)

diff --git a/lib/matplotlib/mathtext.py b/lib/matplotlib/mathtext.py
@@ -55,7 +55,7 @@ def __init__(self, output):
             Whether to return a `VectorParse` ("path") or a
             `RasterParse` ("agg", or its synonym "macosx").
         """
-        self._output_type = _api.check_getitem(
+        self._output_type = _api.getitem_checked(
             {"path": "vector", "agg": "raster", "macosx": "raster"},
             output=output.lower())
 
@@ -89,7 +89,7 @@ def parse(self, s, dpi=72, prop=None, *, antialiased=None):
     def _parse_cached(self, s, dpi, prop, antialiased, load_glyph_flags):
         if prop is None:
             prop = FontProperties()
-        fontset_class = _api.check_getitem(
+        fontset_class = _api.getitem_checked(
             self._font_type_mapping, fontset=prop.get_math_fontfamily())
         fontset = fontset_class(prop, load_glyph_flags)
         fontsize = prop.get_size_in_points()

diff --git a/lib/matplotlib/offsetbox.py b/lib/matplotlib/offsetbox.py
@@ -977,7 +977,7 @@ def __init__(self, loc, *,
         self.set_child(child)
 
         if isinstance(loc, str):
-            loc = _api.check_getitem(self.codes, loc=loc)
+            loc = _api.getitem_checked(self.codes, loc=loc)
 
         self.loc = loc
         self.borderpad = borderpad

diff --git a/lib/matplotlib/quiver.py b/lib/matplotlib/quiver.py
@@ -406,7 +406,7 @@ def draw(self, renderer):
 
     def _set_transform(self):
         fig = self.Q.axes.get_figure(root=False)
-        self.set_transform(_api.check_getitem({
+        self.set_transform(_api.getitem_checked({
             "data": self.Q.axes.transData,
             "axes": self.Q.axes.transAxes,
             "figure": fig.transFigure,
@@ -614,7 +614,7 @@ def _dots_per_unit(self, units):
         """Return a scale factor for converting from units to pixels."""
         bb = self.axes.bbox
         vl = self.axes.viewLim
-        return _api.check_getitem({
+        return _api.getitem_checked({
             'x': bb.width / vl.width,
             'y': bb.height / vl.height,
             'xy': np.hypot(*bb.size) / np.hypot(*vl.size),

diff --git a/lib/matplotlib/scale.py b/lib/matplotlib/scale.py
@@ -290,7 +290,7 @@ def __init__(self, base, nonpositive='clip'):
         if base <= 0 or base == 1:
             raise ValueError('The log base cannot be <= 0 or == 1')
         self.base = base
-        self._clip = _api.check_getitem(
+        self._clip = _api.getitem_checked(
             {"clip": True, "mask": False}, nonpositive=nonpositive)
 
     def __str__(self):
@@ -838,7 +838,7 @@ def scale_factory(scale, axis, **kwargs):
     scale : {%(names)s}
     axis : `~matplotlib.axis.Axis`
     """
-    scale_cls = _api.check_getitem(_scale_mapping, scale=scale)
+    scale_cls = _api.getitem_checked(_scale_mapping, scale=scale)
 
     if _scale_has_axis_parameter[scale]:
         return scale_cls(axis, **kwargs)

diff --git a/lib/matplotlib/testing/jpl_units/UnitDbl.py b/lib/matplotlib/testing/jpl_units/UnitDbl.py
@@ -49,7 +49,7 @@ def __init__(self, value, units):
         - value     The numeric value of the UnitDbl.
         - units     The string name of the units the value is in.
         """
-        data = _api.check_getitem(self.allowed, units=units)
+        data = _api.getitem_checked(self.allowed, units=units)
         self._value = float(value * data[0])
         self._units = data[1]
 
@@ -69,7 +69,7 @@ def convert(self, units):
         """
         if self._units == units:
             return self._value
-        data = _api.check_getitem(self.allowed, units=units)
+        data = _api.getitem_checked(self.allowed, units=units)
         if self._units != data[1]:
             raise ValueError(f"Error trying to convert to different units.\n"
                              f"    Invalid conversion requested.\n"

diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
@@ -1425,7 +1425,7 @@ def __init__(self, ax, label, initial='', *,
         """
         super().__init__(ax)
 
-        self._text_position = _api.check_getitem(
+        self._text_position = _api.getitem_checked(
             {"left": 0.05, "center": 0.5, "right": 0.95},
             textalignment=textalignment)
 

diff --git a/lib/mpl_toolkits/axes_grid1/axes_divider.py b/lib/mpl_toolkits/axes_grid1/axes_divider.py
@@ -439,7 +439,7 @@ def append_axes(self, position, size, pad=None, *, axes_class=None,
         **kwargs
             All extra keywords arguments are passed to the created axes.
         """
-        create_axes, pack_start = _api.check_getitem({
+        create_axes, pack_start = _api.getitem_checked({
             "left": (self.new_horizontal, True),
             "right": (self.new_horizontal, False),
             "bottom": (self.new_vertical, True),