Message290106
When using `copy.copy` to copy an `itertools.chain` instance the results can be weird. For example
>>> from itertools import chain
>>> from copy import copy
>>> a = chain([1,2,3], [4,5,6])
>>> b = copy(a)
>>> next(a) # looks okay
1
>>> next(b) # jumps to the second iterable, not okay?
4
>>> tuple(a)
(2, 3)
>>> tuple(b)
(5, 6)
I don't really want to "copy.copy" such an iterator (I would either use `a, b = itertools.tee(a, 2)` or `b = a` depending on the use-case). This just came up because I investigated how pythons iterators behave when copied, deepcopied or pickled because I want to make the iterators in my extension module behave similarly. |
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Date |
User |
Action |
Args |
2017-03-24 19:14:26 | MSeifert | set | recipients:
+ MSeifert |
2017-03-24 19:14:26 | MSeifert | set | messageid: <1490382866.15.0.806348806156.issue29897@psf.upfronthosting.co.za> |
2017-03-24 19:14:26 | MSeifert | link | issue29897 messages |
2017-03-24 19:14:26 | MSeifert | create | |
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