[Python-ideas] with expression

[Yann Kaiser]

The first one could be accomplished like:

    x = [line.split() for line in f] with open(thisfile) as f

It would keep f opened while the listcomp is being evaluated. This
makes me think however of a likely accident:

    x = (line.split() for line in f) with open('name') as f
    next(x) # ValueError: I/O operation on closed file.

This does mirror this mistake though:

    with open('name') as f:
        return (line.split() for line in f)

When what was meant was:

    with open('name') as f:
        for line in f:
            yield line.split()

(Which is, unfortunately, a __del__ in disguise, which is frowned upon.)

This does raise the question of if we need a "for..in..with" construct
for purposes other than setting a new "highest keyword density" record
:-)