文件json

import json
def op_data(filename,dic=None):
    if dic:#写入进去
       with open(filename,'w',encoding='utf-8') as fw:
           json.dump(dic,fw,ensure_ascii=False,indent=3)#字典转成json
    else:
        with open(filename,encoding='utf-8') as fr:
            return  json.load(fr)#json转成Python类型
FILENAME='user_info.json'
all_users=op_data(FILENAME)
print(all_users)
for i in range(3):
    choice=input('输入，1、注册，2、删除:')
    if choice=='1':
        username=input("username:")
        pwd=input("pwd:")
        if username not in all_users:
            all_users[username]=pwd
            op_data(FILENAME,all_users)
    elif choice=='2':
        username=input("username:")
        all_users.pop(username)
        op_data(FILENAME, all_users)