Question

我正在尝试将字典添加到已有2个字典的json文件中。但这给了我初始文件和结果，它们都放在同一个json文件中。我的代码如下。预先感谢大家。

import json
import os 

cwd = os.getcwd()
fp = cwd + '/xero_credentials.json'

def json_append():
    data_object = {
        "clientName": "Company Test",
        "clientId": "null",
        "clientSecret": "null",
        "redirect_url": "http://localhost:8080/callback",
        'scopes': "offline_access accounting.transactions.read accounting.journals.read",
        'refreshToken': "null"
        }

    with open(fp, 'r+') as json_file:
        data = json.load(json_file)
        data_dictionary = data['credentials']
        data_dictionary.append(data_object)
        json.dump(data, json_file, indent = 4, sort_keys=True)
    json_file.close()

# **********

json_append()

这是结果：

{
    "credentials": [
        {
            "clientName": "C1",
            "clientId": "null"
        },
        {
            "clientName": "C2",
            "clientId": "null"
        }
    ]
}
{
    "credentials": [
        {
            "clientName": "C1",
            "clientId": "null"
        },
        {
            "clientName": "C2",
            "clientId": "null"
        },
        {
            "clientName": "C3",
            "clientId": "null"
        }
    ]
}

Answer 1

很难就地更新文件（某些特殊情况除外），因此通常通常必须先将其全部内容读取到内存中，然后进行更新，然后使用它重写整个文件。

>

这是我的意思：

import json
import os

cwd = os.getcwd()
fp = cwd + '/xero_credentials.json'

def json_append():
    data_object = {
        "clientName": "Company Test",
        "clientId": "null",
        "clientSecret": "null",
        "redirect_url": "http://localhost:8080/callback",
        'scopes': "offline_access accounting.transactions.read accounting.journals.read",
        'refreshToken': "null"
        }

    # Read the entire file.
    with open(fp, 'r') as json_file:
        data = json.load(json_file)

    # Update the data read.
    credentials = data['credentials']
    credentials.append(data_object)

    # Update the file by rewriting it.
    with open(fp, 'w') as json_file:
        json.dump(data, json_file, indent=4, sort_keys=True)


json_append()

更新的文件：

{
    "credentials": [
        {
            "clientId": "null",
            "clientName": "C1"
        },
        {
            "clientId": "null",
            "clientName": "C2"
        },
        {
            "clientId": "null",
            "clientName": "Company Test",
            "clientSecret": "null",
            "redirect_url": "http://localhost:8080/callback",
            "refreshToken": "null",
            "scopes": "offline_access accounting.transactions.read accounting.journals.read"
        }
    ]
}

Answer 2

编辑：误解了这个问题。

问题是打开文件时正在使用“ r +”模式。这意味着您将能够读取和追加但不能编辑，这就是您要尝试做的。

只需使用with open(fp, 'w')。

此外，您无需显式关闭文件。一旦离开范围，诸如with之类的上下文管理器就会自动执行此操作。

将字典追加到JSON文件

2 个答案: