MNT: use a property rather than assignment to manage alias

tacaswell · tacaswell · commit cef64ad12ea0 · 2022-03-31T18:14:31.000-04:00
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -949,13 +949,16 @@ def clear(self, keep_observers=False):
 
         self.stale = True
 
-    # synonym for `clear`.
-    clf = clear
+    # synonym for `clear`.  We do this with a property to make sure that we get
+    # a literal alias that correctly behaves for sub-classes (without resorting
+    # to __subclass_init__ or other meta-programming tools.
+    @property
+    def clf(self):
+        return self.clear
 
     # Note: in the docstring below, the newlines in the examples after the
     # calls to legend() allow replacing it with figlegend() to generate the
     # docstring of pyplot.figlegend.
-
     @_docstring.dedent_interpd
     def legend(self, *args, **kwargs):
         """
@@ -2848,9 +2851,6 @@ def clear(self, keep_observers=False):
         if toolbar is not None:
             toolbar.update()
 
-    # synonym for `clear`.
-    clf = clear
-
     @_finalize_rasterization
     @allow_rasterization
     def draw(self, renderer):
diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
@@ -791,10 +791,12 @@ def test_figure_clear():
 
 
 def test_clf_is_clear():
-    for cls in [FigureBase] + FigureBase.__subclasses__():
-        assert cls.clf is cls.clear
-        assert cls.clear.__name__ == 'clear'
+    fig = Figure()
+    subfig = fig.subfigures()
 
+    for f in [fig, subfig]:
+        assert f.clear.__func__ is f.clf.__func__
+        assert f.clear.__func__.__name__ == 'clear'
 
 @mpl.style.context('mpl20')
 def test_picking_does_not_stale():
