allsegs and allkinds return individual segments

rcomer · rcomer · commit 5c35af176882 · 2023-09-25T11:32:20.000+01:00
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -935,9 +935,11 @@ def __init__(self, ax, *args,
             )
 
     allsegs = _api.deprecated("3.8", pending=True)(property(lambda self: [
-        p.vertices for c in self.collections for p in c.get_paths()]))
+        [subp.vertices for subp in p._iter_connected_components()]
+        for p in self.get_paths()]))
     allkinds = _api.deprecated("3.8", pending=True)(property(lambda self: [
-        p.codes for c in self.collections for p in c.get_paths()]))
+        [subp.codes for subp in p._iter_connected_components()]
+        for p in self.get_paths()]))
     tcolors = _api.deprecated("3.8")(property(lambda self: [
         (tuple(rgba),) for rgba in self.to_rgba(self.cvalues, self.alpha)]))
     tlinewidths = _api.deprecated("3.8")(property(lambda self: [
diff --git a/lib/matplotlib/tests/test_contour.py b/lib/matplotlib/tests/test_contour.py
@@ -819,6 +819,20 @@ def test_all_nan():
                                 2.4e-14, 5e-14, 7.5e-14, 1e-13])
 
 
+def test_allsegs_allkinds():
+    x, y = np.meshgrid(np.arange(0, 10, 2), np.arange(0, 10, 2))
+    z = np.sin(x) * np.cos(y)
+
+    cs = plt.contour(x, y, z, levels=[0, 0.5])
+
+    # Expect two levels, first with 5 segments and the second with 4.
+    with pytest.warns(PendingDeprecationWarning, match="all"):
+        for result in [cs.allsegs, cs.allkinds]:
+            assert len(result) == 2
+            assert len(result[0]) == 5
+            assert len(result[1]) == 4
+
+
 def test_deprecated_apis():
     cs = plt.contour(np.arange(16).reshape((4, 4)))
     with pytest.warns(mpl.MatplotlibDeprecationWarning, match="collections"):
