以下是一些关于itertools.tee
:
li = [x for x in range(10)]
ite = iter(li)
==================================================
it = itertools.tee(ite, 5)
>>> type(ite)
<type 'listiterator'>
>>> type(it)
<type 'tuple'>
>>> type(it[0])
<type 'itertools.tee'>
>>>
>>> list(ite)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(it[0]) # here I got nothing after 'list(ite)', why?
[]
>>> list(it[1])
[]
====================play again===================
>>> ite = iter(li)
it = itertools.tee(ite, 5)
>>> list(it[1])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(it[2])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(it[3])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(it[4])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(ite)
[] # why I got nothing? and why below line still have the data?
>>> list(it[0])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(it[0])
[]
====================play again===================
>>> ite = iter(li)
itt = itertools.tee(it[0], 5) # tee the iter's tee[0].
>>> list(itt[0])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(itt[1])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(it[0])
[] # why this has no data?
>>> list(it[1])
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list(ite)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
我的问题是
- tee 是如何工作的,为什么有时原始迭代器“有数据”而其他时候没有?
- 我可以将迭代深度副本保留为“状态种子”以保持原始迭代器状态并将其用于以后使用吗?
- 我可以交换 2 个 iters 或 2 个
itertools.tee
吗?
谢谢!