Use standard property alias machinery in contour().

Note that 'color(s)' remains special-cased because the ContourSet
constructor needs to do a fair bit of special wrangling for it.

Author: anntzer

lib/matplotlib/contour.py

@@ -602,7 +602,7 @@ def __init__(self, ax, *args,
                  hatches=(None,), alpha=None, origin=None, extent=None,
                  cmap=None, colors=None, norm=None, vmin=None, vmax=None,
                  colorizer=None, extend='neither', antialiased=None, nchunk=0,
-                 locator=None, transform=None, negative_linestyles=None, clip_path=None,
+                 locator=None, transform=None, negative_linestyles=None,
                  **kwargs):
         """
         Draw contour lines or filled regions, depending on
@@ -656,7 +656,6 @@ def __init__(self, ax, *args,
         super().__init__(
             antialiaseds=antialiased,
             alpha=alpha,
-            clip_path=clip_path,
             transform=transform,
             colorizer=colorizer,
         )
@@ -672,6 +671,9 @@ def __init__(self, ax, *args,
         self.nchunk = nchunk
         self.locator = locator
 
+        if "color" in kwargs:
+            raise _api.kwarg_error("ContourSet.__init__", "color")
+
         if colorizer:
             self._set_colorizer_check_keywords(colorizer, cmap=cmap,
                                                norm=norm, vmin=vmin,
@@ -764,23 +766,20 @@ def __init__(self, ax, *args,
                 _api.warn_external('linewidths is ignored by contourf')
             # Lower and upper contour levels.
             lowers, uppers = self._get_lowers_and_uppers()
-            self.set(
-                edgecolor="none",
-                # Default zorder taken from Collection
-                zorder=kwargs.pop("zorder", 1),
-                rasterized=kwargs.pop("rasterized", False),
-            )
+            self.set(edgecolor="none")
+            self.set(**kwargs)  # Let user-set values override defaults.
 
         else:
             self.set(
                 facecolor="none",
                 linewidths=self._process_linewidths(linewidths),
                 linestyle=self._process_linestyles(linestyles),
+                label="_nolegend_",
                 # Default zorder taken from LineCollection, which is higher
                 # than for filled contours so that lines are displayed on top.
-                zorder=kwargs.pop("zorder", 2),
-                label="_nolegend_",
+                zorder=2,
             )
+            self.set(**kwargs)
 
         self.axes.add_collection(self, autolim=False)
         self.sticky_edges.x[:] = [self._mins[0], self._maxs[0]]
@@ -790,12 +789,6 @@ def __init__(self, ax, *args,
 
         self.changed()  # set the colors
 
-        if kwargs:
-            _api.warn_external(
-                'The following kwargs were not used by contour: ' +
-                ", ".join(map(repr, kwargs))
-            )
-
     allsegs = property(lambda self: [
         [subp.vertices for subp in p._iter_connected_components()]
         for p in self.get_paths()])

lib/matplotlib/tests/test_contour.py

@@ -865,3 +865,15 @@ def test_contourf_rasterize():
     circle = mpatches.Circle([0.5, 0.5], 0.5, transform=ax.transAxes)
     cs = ax.contourf(data, clip_path=circle, rasterized=True)
     assert cs._rasterized
+
+
+@check_figures_equal(extensions=["png"])
+def test_contour_aliases(fig_test, fig_ref):
+    data = np.arange(100).reshape((10, 10)) ** 2
+    fig_test.add_subplot().contour(data, linestyle=":")
+    fig_ref.add_subplot().contour(data, linestyles="dotted")
+
+
+def test_contour_singular_color():
+    with pytest.raises(TypeError):
+        plt.figure().add_subplot().contour([[0]], color="r")