嵌套循环以及break和continue

嵌套循环试验（打印九九表）

row = 1
line = 1
while row <= 9:
    line = 1
    while line <= row:
        print(f'{line}*{row}={row * line}',end=' ')
        line += 1
    print()
    row += 1

break实验（登录系统）

• 说明：跳出就近的循环

count = 0
while True:
    use_name = 'adc'
    pass_word = '123'
    u = input('请输入用户名：')
    p = input('请输入密码：')
    if (u == use_name) and (p == pass_word):
        print('成功登陆')
        break
    else:
        count += 1
        if (3 - count) == 0:
            print('3次输入错误,锁定')
            break
        print(f'用户名或密码输入错误!你还有{3 - count}次机会')

continue实验

• 说明：结束本次循环，进入下一次循环
• 注意：容易死锁，一般不用

n = 1
while n < 4:
    if n == 2:
        n += 1
        continue
    print(n,end=' ')   #打印结果1 3
    n += 1