芙玉宝给你玉一样的肌肤
问题描述
我想通过一个迭代器反复(N 次)循环遍历一个列表，以免在内存中实际存储 N 个列表副本.有没有一种内置的或优雅的方法可以在不编写我自己的生成器的情况下做到这一点?
I'd like to cycle through a list repeatedly (N times) via an iterator, so as not to actually store N copies of the list in memory. Is there a built-in or elegant way to do this without writing my own generator?
理想情况下， itertools.cycle(my_list) 会有第二个参数来限制它循环的次数......唉，没有这样的运气.
Ideally, itertools.cycle(my_list) would have a second argument to limit how many times it cycles... alas, no such luck.
推荐答案
import itertools itertools.chain.from_iterable(itertools.repeat([1, 2, 3], 5))
Itertools 是一个很棒的库.:)
Itertools is a wonderful library. :)
