Update lib/matplotlib/contour.py

chahak13 · tacaswell · chahak13 · commit cba8e7da0fe6 · 2022-12-17T10:27:25.000+05:30
Co-authored-by: Thomas A Caswell &lt;tcaswell@gmail.com&gt;
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -1456,8 +1456,10 @@ def _contour_args(self, args, kwargs):
                 kwargs
             )
         elif (("X" in kwargs) ^ ("Y" in kwargs)) and "Z" in kwargs:
-            raise KeyError("Both 'X' and 'Y' must be passed as kwargs. "
-                           "Passing only one of the two is not allowed.")
+            raise TypeError(
+                "Both or neither 'X' and 'Y' may be passed as kwargs. "
+                "Passing only one of the two is not allowed."
+            )
         elif "Z" in kwargs:
             z = ma.asarray(kwargs.pop("Z"), dtype=np.float64)
             x, y = self._initialize_x_y(z)
diff --git a/lib/matplotlib/tests/test_contour.py b/lib/matplotlib/tests/test_contour.py
@@ -710,7 +710,8 @@ def test_contour_xyz_kwargsonly():
 
 
 def test_contour_either_xy():
-    with pytest.raises(KeyError, match="Both 'X' and 'Y' must be passed"):
+    with pytest.raises(TypeError,
+                       match="Both or neither 'X' and 'Y' may be passed"):
         plt.contour(
             X=np.random.rand(30, 30),
             Z=np.random.rand(30, 30)
