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=Falsefor 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=Falsecount=0while 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...")