python islice()

islice()获取迭代器的切片，消耗迭代器

语法：

islice(iterable, [start, ] stop [, step]):

例1：

from itertools import islice

a = [1, 2, 3, 4, 5, 6, 7, 8, 9]
a_ite = iter(a)

print(list(islice(a_ite,0,3)))
print(list(islice(a_ite,0,3)))
print(list(islice(a_ite,0,3)))

 

例2：

 

 

 

from itertools import islice

with open('E:/test/1.txt', 'r') as f:
    for line in islice(f, 0, 3):
        print(line)
    print('***')
    for line in islice(f, 0, 3):
        print(line)
    print('***')
    for line in islice(f, 0, 3):
        print(line)