[Python-Dev] Python3 compiled listcomp can't see local var - bug or feature?
ericfahlgren at gmail.com
Mon Jun 11 18:31:03 EDT 2018
On Mon, Jun 11, 2018 at 3:10 PM Rob Cliffe via Python-Dev <
python-dev at python.org> wrote:
> Skip, I think you have misunderstood the point I was making. It was
> not whether the loop variable should leak out of a list comprehension.
> Rather, it was whether a local variable should, so to speak, "leak into"
> a list comprehension. And the answer is: it depends on whether the code
> is executed normally, or via exec/eval. Example:
> def Test():
> x = 1
> print([x+i for i in range(1,3)]) # Prints [2,3]
> exec('print([x+i for i in range(1,3)])') # Raises NameError (x)
> I (at least at first) found the difference in behaviour surprising.
Change 'def' to 'class' and run it again. You'll be even more surprised.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Python-Dev