itertools模块

from itertools import count, cycle, repeat, chain

# 无限迭代器
for i in count(10, 2):
    if i > 20:
        break
    print(i)  # 10, 12, 14, 16, 18, 20

# 组合器
list(chain([1, 2], [3, 4]))  # [1, 2, 3, 4]

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