[Python-Dev] Iteration variables and list comprehensions

[Greg Ward]

On 29 May 2001, David Beazley said:
> Therefore, I'm wondering if it would make any sense to make the
> iterator variables used inside of a list comprehension private in some
> manner--either through name mangling or some other technique? For
> example:

Two ideas occur to me:
  * make the list comprehension a new scoping level, which of course
    is doable now that we have sensible scoping semantics.  Presumably
    the usual warning message about shadowing variables from an
    outer scope will apply; you'll still have the bug in your code,
    but at least Python will tell you about it

  * don't make list comprehensions a separate scope, but add a
    little trickery so that something *like* the "shadowing variable
    from an outer scope" message is emitted

Haven't really thought about backwards compatibility issues...

        Greg