from itertools import product,takewhile

a = [1,2,3]
b = [1,2,3]
c = [1,2,3]

#嵌套循環(huán)，當(dāng)滿足某個(gè)條件時(shí)執(zhí)行
for aa,bb,cc in product(a,b,c):
    if aa+bb+cc == 9:
        print(aa,bb,cc)


#自定義一個(gè)方法，返回真則繼續(xù)，不為真則break
def check_num(num):
    if num<3:
        return True
    return False

for i in takewhile(check_num,a):
    print(i)
            
          

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