Guido> Here's the rule I'd propose for iterator comprehensions, which list Guido> comprehensions would inherit:
Guido> [<expr1> for <vars> in <expr2>]
Guido> The variables in <vars> should always be simple variables, and Guido> their scope only extends to <expr1>. If there's a variable with Guido> the same name in an outer scope (including the function Guido> containing the comprehension) it is not accessible (at least not Guido> by name) in <expr1>. <expr2> is not affected.
I thought the definition for list comprehension syntax was something like
'[' <expr> for <vars> in <expr> [ for <vars> in <expr> ] * [ if <expr> ] * ']'
The loop <vars> in an earlier for clause should be visible in all nested for clauses and conditional clauses, not just in the first <expr>.