通过标志位跳出多层循环

break只能跳出本层循环，若要跳出多层循环，可定义个标志位break_flag

跳出多层for循环：

break_flag=False
for i in range(10):
    print("爷爷层",i)
    for j in range(10):
        print("爸爸层",j)
        if j == 3:
            break_flag=True
            break
        for k in range(10):
            print("孙子层",k)
            if k ==2:
                break_flag=True
                break
        if break_flag:
            print("儿子蒙了，不活了...")
            break
    if break_flag:
        print("儿子蒙了，不活了...")
        break

跳出while多层循环：

break_flag=False
count=0
while break_flag==False:
    print("爷爷层...")
    while break_flag==False:
        print("爸爸层...")
        while break_flag==False:
            count+=1
            if count>10:
                break_flag=True
            print("孙子层...")

print("keep going...")