Python json.decoder.JSONDecodeError：额外数据

Question

我正在编写一个充当登录屏幕的简单程序。作为其中的一部分，我让用户创建一个帐户，该帐户将在 JSON 文档中保存他们的姓名、年龄、城市和登录信息。我已经能够很容易地写入 JSON，但是每当我从文件中读取时，它都会抛出“额外数据错误”并说它在第 2 行第 14 列

我正在使用 python 3.8.2，如果有帮助的话

这是中的代码main.py

import json

def read(accList):

    with open('acc.json') as accountFile:

        first = accountFile.read(1)

        if not first:

            print("No accounts")

        else:

            accList["account"]=json.load(accountFile)

    accountFile.close()

    return(accList)

def write(accList):

    with open('acc.json',"w") as accountFile:

        accountFile.write(json.dumps(accList, indent = 4, sort_keys=True))

    accountFile.close()

def login(accList):

    accList=read(accList)

    user=input("Please enter your username: ")

    password=input("Please enter your password: ")

def create(accList):

    accList=read(accList)

    name=input("Please enter your name: ")

    age =input("How old are you: ")

    city = input("What city do you live in: ")

    user=input("Please create a username: ")

    password=input("Please create a  password: ")

    accList["account"].append({

        "name": name,

        "age": age,

        "city": city,

        "username": user,

        "password": password

    })

    write(accList)

def main():

    accList = {}

    accList["account"] = []

    returning=input("Welcome to Cael's login screen.\nDo you already have an account? ")

    if(returning.lower()=="yes"):

        login(accList)

    elif(returning.lower()=="no"):

        create(accList)

    #else:

     #   print("Sorry that's not a valid answer. Please only type \'Yes\' or \'No\'.")

main()

这是我在 JSON 中的输出（注意：添加一个帐户可以正常工作，但之后会抛出错误）

{

    "account": [

        {

            "age": "52",

            "city": "Jerome",

            "name": "Maynard",

            "password": "pass",

            "username": "mjkeenan"

        }

    ]

}

抱歉，如果这看起来有点愚蠢，或者存在明显的错误。我对整个 JSON 文件还是陌生的

Answer 1

该错误是因为一旦您读取文件，指针将在末尾，所以这就是发生该错误的原因，并且在调试后抛出了另一个错误，即dict对象没有append方法，我只是调试了它import jsondef read(accList):    with open('acc.json') as accountFile:        first = accountFile.read(1)        # This will make the pointer to point at the beggining of the file        accountFile.seek(0)        if not first:            print("No accounts")        else:            # this is to access only the account list and not the whole dictionary            accList["account"]=json.load(accountFile)["account"]    accountFile.close()    return(accList)def write(accList):    with open('acc.json',"w") as accountFile:        accountFile.write(json.dumps(accList, indent = 4, sort_keys=True))    accountFile.close()def login(accList):    accList=read(accList)    user=input("Please enter your username: ")    password=input("Please enter your password: ")def create(accList):    accList=read(accList)    name=input("Please enter your name: ")    age =input("How old are you: ")    city = input("What city do you live in: ")    user=input("Please create a username: ")    password=input("Please create a  password: ")    accList["account"].append({        "name": name,        "age": age,        "city": city,        "username": user,        "password": password    })    write(accList)def main():    accList = {}    accList["account"] = []    returning=input("Welcome to Cael's login screen.\nDo you already have an account? ")    if(returning.lower()=="yes"):        login(accList)    elif(returning.lower()=="no"):        create(accList)    #else:     #   print("Sorry that's not a valid answer. Please only type \'Yes\' or \'No\'.")main()