[Python-Dev] accumulator display syntax

[Tim Peters]

[Guido]
> ...
> BTW, while Alex has shown that a generator function with no free
> variables runs quite fast, a generator expression that uses variables
> from the surrounding scope will have to use the nested scopes
> machinery to access those, unlike a list comprehension; not only does
> this run slower, but it also slows down all other uses of that
> variable in the surrounding scope (because it becomes a "cell"
> throughout the scope).

The implementation could synthesize a generator function abusing default
arguments to give the generator's frame locals with the same names.