Merge pull request matplotlib#20731 from deep-jkl/path-copy

Improved implementation of Path.copy and deepcopy

Author: timhoffm

lib/matplotlib/path.py

@@ -9,6 +9,7 @@
 visualisation.
 """
 
+import copy
 from functools import lru_cache
 from weakref import WeakValueDictionary
 
@@ -259,16 +260,13 @@ def readonly(self):
         """
         return self._readonly
 
-    def __copy__(self):
+    def copy(self):
         """
         Return a shallow copy of the `Path`, which will share the
         vertices and codes with the source `Path`.
         """
-        import copy
         return copy.copy(self)
 
-    copy = __copy__
-
     def __deepcopy__(self, memo=None):
         """
         Return a deepcopy of the `Path`.  The `Path` will not be

lib/matplotlib/tests/test_path.py

@@ -1,4 +1,3 @@
-import copy
 import re
 
 import numpy as np
@@ -333,8 +332,28 @@ def test_path_deepcopy():
     codes = [Path.MOVETO, Path.LINETO]
     path1 = Path(verts)
     path2 = Path(verts, codes)
-    copy.deepcopy(path1)
-    copy.deepcopy(path2)
+    path1_copy = path1.deepcopy()
+    path2_copy = path2.deepcopy()
+    assert path1 is not path1_copy
+    assert path1.vertices is not path1_copy.vertices
+    assert path2 is not path2_copy
+    assert path2.vertices is not path2_copy.vertices
+    assert path2.codes is not path2_copy.codes
+
+
+def test_path_shallowcopy():
+    # Should not raise any error
+    verts = [[0, 0], [1, 1]]
+    codes = [Path.MOVETO, Path.LINETO]
+    path1 = Path(verts)
+    path2 = Path(verts, codes)
+    path1_copy = path1.copy()
+    path2_copy = path2.copy()
+    assert path1 is not path1_copy
+    assert path1.vertices is path1_copy.vertices
+    assert path2 is not path2_copy
+    assert path2.vertices is path2_copy.vertices
+    assert path2.codes is path2_copy.codes
 
 
 @pytest.mark.parametrize('phi', np.concatenate([