[Python-Dev] Make "global after use" a SyntaxError

Hi all, The documentation at https://docs.python.org/3/reference/simple_stmts.html says that: "Names listed in a global statement must not be used in the same code block textually preceding that global statement" But then later: "CPython implementation detail: The current implementation does not enforce the two restrictions, but programs should not abuse this freedom, as future implementations may enforce them..." Code like this def f(): x = 1 global x gives SyntaxWarning for several releases, maybe it is time to make it a SyntaxError? (I have opened an issue for this http://bugs.python.org/issue27999 I will submit a patch soon). -- Ivan