python itertools函数的多种用法

import itertools

countries = ['USA', 'Australia', 'Canada','Germany']

result = itertools.combinations(countries, 3)

for i in result:

print(i)

import itertools country

= ['USA', 'Australia', 'Canada','Germany']

result = itertools.combinations_with_replacement(countries, 3)

for i in result:

print(i)

在 itertools.count(20,4) 中为 i导入 itertools :

    print(i)

    if i > 30:

        Break

import itertools

countries = [("West", "USA"),  

          ("West", "Canada"),  

          ("East", "Singapore"),  

          ("East", "China")]

iterator_one = itertools.groupby (countries, lambda x : x[0])

for key, group in iterator_one:

    result = {key : list(group)}

    print(result)