Python入门习题大全——验证用户

Python入门习题大全——索引

没有用户文件时，询问用户姓名并存储
当用户文件存在时，读取文件中的用户名，询问使用者是否为该用户
若是，则输出欢迎信息，若不是，则询问用户名并存储

# 验证用户
import json

def get_stored_username():
    filename = 'username.json'
    try:
        with open(filename) as f_obj:
            username = json.load(f_obj)
    except FileNotFoundError:
        return None
    else:
        return username

def get_new_username():
    username = input("What is your name? ")
    filename = 'username.json'
    with open(filename, 'w') as f_obj:
        json.dump(username, f_obj)
    return username

def greet_user():
    username = get_stored_username()
    if username:
        print(username + '?')
        print("(输入y或n)")
        n = input()
        if n == 'y':
            print("Welcome back, " + username + "!")
        else:
            username = get_new_username()
            print("We'll remember you when you come back, " + username + "!")
    else:
        username = get_new_username()
        print("We'll remember you when you come back, " + username + "!")

greet_user()