Login用户登录（Python实现）

 username_fault = "isuperSun"      #程序存储用户名和密码
 password_fault = "

 counts = 0
 while counts<3:
     username = input("Username:")
     password = input("Password:")
     if username == username_fault and password == password_fault:    #若用户名和密码输入正确，登录成功
         print("Welcome...")
         break
     else:
         print("Invalid username or password.")
     counts += 1
     if counts == 3:                                                  #输入密码失败三次后，是否再输入？
         answer = input("Do you want to try again?[y/n]")
     else:
         answer = "n"
     if answer == "y":
         counts = 0
 else:
     print("You are so stupid!")

登录成功：

登录失败：