append() 函数在尝试删除 json 文件中的重复项时不起作用 - Python

Question

我有一个 json 文件，其中有一些基于名为 userid 的列的重复项，并且希望使用append() 函数删除这些重复项，以便它可以输出与原始文件格式相同的新文件。

这是一个json文件：

    [
        {
            "userid": "7126521576",
            "status": "UserStatus.OFFLINE",
            "name": "Avril Pauling",
            "bot": false,
            "username": "None"
        },
      {
            "userid": "7126521576",
            "status": "UserStatus.OFFLINE",
            "name": "Avril Pauling",
            "bot": false,
            "username": "None"
        },
        {
            "userid": "6571627119",
            "status": "UserStatus.OFFLINE",
            "name": "Laverne Alferez",
            "bot": false,
            "username": "None"
        },
        {
            "userid": "1995422560",
            "status": "UserStatus.OFFLINE",
            "name": "098767800",
            "bot": false,
            "username": "None"
        }
    ]

删除重复的用户ID后的输出文件应该是：

    [
        {
            "userid": "7126521576",
            "status": "UserStatus.OFFLINE",
            "name": "Avril Pauling",
            "bot": false,
            "username": "None"
        },
        {
            "userid": "6571627119",
            "status": "UserStatus.OFFLINE",
            "name": "Laverne Alferez",
            "bot": false,
            "username": "None"
        },
        {
            "userid": "1995422560",
            "status": "UserStatus.OFFLINE",
            "name": "098767800",
            "bot": false,
            "username": "None"
        }
    ]

我尝试了以下代码，append()函数似乎无法正常工作；它只附加最后一项：

    import json
    with open('target_user.json', 'r', encoding='utf-8') as f:
        jsons = json.load(f)

    jsons2 = []
    for item in jsons:
        if item['userid'] not in json2:
            jsons2.append(item)
            
    with open('target_user2.json', 'w', encoding='utf-8') as nf:
        json.dump(jsons2, nf, indent=4)

非常感谢快速帮助。

Answer 1

这应该可以满足您的需要：

import json
with open('target_user.json', 'r', encoding='utf-8') as f:
    jsons = json.load(f)

ids = set()
jsons2 = []
for item in jsons:
    if item['userid'] not in ids:
        ids.add(item['userid'])
        jsons2.append(item)
        
with open('target_user2.json', 'w', encoding='utf-8') as nf:
    json.dump(jsons2, nf, indent=4)