从Json Dict/Python中删除密钥

我刚开始写这个剧本练习， 它将接受输入，然后将其写入Json文件中。 代码如下所示：

import json


command = int(input("Do You Want To Add, Or Remove From List? 1/2 "))
if command == 1:
    add_key = input("Type In key Name: ")
    add_val1 = input("Type In Value N1: ")
    add_val2 = input("Type In Value N2: ")

    with open('jjj.json', 'r+') as jjson:
        tvsh = json.load(jjson)
        new_tvsh = {add_key: [add_val1, add_val2]}
        tvsh.update(new_tvsh)
        jjson.seek(0)
        json.dump(tvsh, jjson)
elif command == 2:
    with open('jjj.json', 'r+') as jjson:
        tvsh = json.load(jjson)
        chooseremove = input("Choose Key To Remove: ")
        try:
            del tvsh[chooseremove]
        except KeyError as ex:
            print(f"No such key: {chooseremove} ")
        jjson.seek(0)
        json.dump(tvsh, jjson)

{"Key1":["Val1","Val2"],"Key2":["Val1","Val2"]} "Key3":["Val1","Val2"]}

Json文件如下所示：

{"Key1":["Val1","Val2"],"Key2":["Val1","Val2"],"Key3":["Val1","Val2"]}

但当我尝试删除密钥（例如key3）时，我的json文件将如下所示：

import json


command = int(input("Do You Want To Add, Or Remove From List? 1/2 "))
if command == 1:
    add_key = input("Type In key Name: ")
    add_val1 = input("Type In Value N1: ")
    add_val2 = input("Type In Value N2: ")

    with open('jjj.json', 'r+') as jjson:
        tvsh = json.load(jjson)
        new_tvsh = {add_key: [add_val1, add_val2]}
        tvsh.update(new_tvsh)
        jjson.seek(0)
        json.dump(tvsh, jjson)
elif command == 2:
    with open('jjj.json', 'r+') as jjson:
        tvsh = json.load(jjson)
        chooseremove = input("Choose Key To Remove: ")
        try:
            del tvsh[chooseremove]
        except KeyError as ex:
            print(f"No such key: {chooseremove} ")
        jjson.seek(0)
        json.dump(tvsh, jjson)

{"Key1":["Val1","Val2"],"Key2":["Val1","Val2"]} "Key3":["Val1","Val2"]}

它在dict外取key，但在末尾加“}” 你知道我能做什么吗

---

编辑：也尝试了.pop，但结果相同这里的错误是运行

jjson.seek（0）

然后运行

json.dump（tvsh，jjson）

不会破坏现有文件的内容，它只会覆盖它。由于删除

Key3

后写入JSON文件的数据结构较小，因此不会覆盖整个文件（即

“Key3”：[“Val1”，“Val2”]}

是第一次写入时留下的）

这里的解决方案是在运行

json.dump（tvsh，jjson）

之后运行

jjson.truncate（）

以下程序显示了差异，但不取决于用户输入：

#!/usr/bin/env python3

import json

# Test data
initial_data = {
    "Key1":["Val1", "Val2"],
    "Key2":["Val1", "Val2"],
    "Key3":["Val1", "Val2"],
}
final_data = {
    "Key1":["Val1", "Val2"],
    "Key2":["Val1", "Val2"],
}

with open('testA.json', 'w') as f:
    json.dump(initial_data, f)
    f.seek(0)
    json.dump(final_data, f)

with open('testB.json', 'w') as f:
    json.dump(initial_data, f)
    f.seek(0)
    json.dump(final_data, f)
    f.truncate()

尝试创建一个，它不接受用户输入，只执行运行时重现问题所需的操作。