Merge pull request #15877 from anntzer/rctbchain

tacaswell · web-flow · commit bb3c0b521a29 · 2019-12-08T13:45:19.000-05:00
MNT: Suppress exception chaining on rc validator failure.
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -767,7 +767,7 @@ def __setitem__(self, key, val):
             try:
                 cval = self.validate[key](val)
             except ValueError as ve:
-                raise ValueError("Key %s: %s" % (key, str(ve)))
+                raise ValueError(f"Key {key}: {ve}") from None
             dict.__setitem__(self, key, cval)
         except KeyError:
             raise KeyError(
