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Comment by pansa2 | Hacker News Reader

There are some exceptions to this - for example, the iteration variable(s) in a list comprehension are only in scope within the comprehension.

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Worth noting that this was _fixed_ in Python 3.

In Python 2.7 you get this:

    >>> my_list = [x for x in 'hello']
    >>> x
    'o'

Thanks, I didn't realize that. That makes their choice really baffling.

The explanation is that (in Python 3) list comprehensions are really just syntactic sugar for generator expressions. In Python, "scope" is really a synonym for "dictionary attached to some object", so generators can have local variables (since they have their own internal scope), but purely syntactic constructs cannot.

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