This is from Python built from the py3k branch:
>>> c = (lambda : i for i in range(11, 16))
>>> for q in c:
... print(q())
...
11
12
13
14
15
>>> # This is expected
>>> c = (lambda : i for i in range(11, 16))
>>> d = list(c)
>>> for q in d:
... print(q())
...
15
15
15
15
15
>>> # I was very surprised
Looking at the implementation, I see why this happens:
>>> c = (lambda : i for i in range(11, 16))
>>> for q in c:
... print(id(q.__closure__[0]))
...
3847792
3847792
3847792
3847792
3847792
>>> # The same closure is used by every lambda
But it seems very odd to me and it can lead to some problems that are a
real pain in the ass to debug.
Cheers,
Brian
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