python自学第四天之字符串方法运用场景

1. 用户登录

mu_user = 'alex'
my_pwd = 'alexchuncai'
my_yzm = 'o98k'
count = 1
while 1:
    user = input("请输入用户名:").strip()
    pwd = input("请输入密 码:").strip()
    if my_user == user and my_pwd == pwd:
        print("登陆成功!")
        break
        yzm = input("请输入验证码(o98k):")
        if yzm.upper() == my_yzm.upper():
            if my_user == user and my_pwd == pwd:
                print("登陆成功!")
                break
            else:
                print("验证码错误!")
    else:
        print("用户名或密码错误!")
    count = count + 1

2. 判断整数小数

num = input("请输入数字:")
if num.count('.') == 1 and not num.startswith('.') and not num.endswith('.'):
    print("这是小数",num)
elif num.isdigit():
    print("这是整数",num)
else:
    print("你傻啊，都告诉你数字了！")