将切片符号与collections.deque一起使用

将切片符号与collections.deque一起使用

import itertools
output = list(itertools.islice(q, 3, 7))

例如：

>>> import collections, itertools>>> q = collections.deque(xrange(10, 20))>>> qdeque([10, 11, 12, 13, 14, 15, 16, 17, 18, 19])>>> list(itertools.islice(q, 3, 7))[13, 14, 15, 16]

与到目前为止发布的其他解决方案相比，这应该更有效。证明？

[me@home]$ SETUP="import itertools,collections; q=collections.deque(xrange(1000000))"[me@home]$ python -m timeit  "$SETUP" "list(itertools.islice(q, 10000, 20000))"10 loops, best of 3: 68 msec per loop[me@home]$ python -m timeit "$SETUP" "[q[i] for i in  xrange(10000, 20000)]"10 loops, best of 3: 98.4 msec per loop[me@home]$ python -m timeit "$SETUP" "list(q)[10000:20000]"10 loops, best of 3: 107 msec per loop