bpo-40593: Improve syntax errors for invalid characters in source code. (GH-20033)

diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py
index ac5aa9a..e0bb5b5 100644
--- a/Lib/test/test_fstring.py
+++ b/Lib/test/test_fstring.py
@@ -583,7 +583,7 @@
                              ])
 
         # Different error message is raised for other whitespace characters.
-        self.assertAllRaise(SyntaxError, 'invalid character in identifier',
+        self.assertAllRaise(SyntaxError, r"invalid non-printable character U\+00A0",
                             ["f'''{\xa0}'''",
                              "\xa0",
                              ])