python 课堂笔记-if语句

# Author:zyl
_username = 'zyl'
_password = 'zyl123'
username = input("username:")

password = input("password:")
print(username, password)
if _username == username and _password == password:
    print("welcome  user  {name} login...".format(name=username))
else:
    print("invalid  usernaem or  password!")

# indentationError表示缩进错误
# if和else后都必须加冒号“：”

age_of_oldboy = 56
guess_age = int(input("guess age:"))  # 强制转换数据类型
if guess_age == age_of_oldboy:
    print("yes,you got it.")
elif guess_age > age_of_oldboy:
    print("think smaller...")
else:
    print("think  bigger!")