如何用Python根据日期值中的年份删除指定JSON对象？

需求说明 #

有一个存储交易数据的JSON文件，结构中transactions下包含多个键值对，值为交易对象列表，每个交易对象含transaction_date字段（格式如MM/DD/YYYY）。需要删除所有日期在2022年之前的交易对象，仅保留2022年及以后的记录。原代码逻辑错误，无法正确识别日期中的年份，需修改实现需求。

示例输入JSON #

{
    "transactions": {
        "0": [
            {
                "transaction_date": "11/29/2022",
                "asset_description": "Western Asset Inflation-Linked Opportunities & Inc",
                "asset_type": "Stock",
                "type": "Sale (Full)",
                "amount": "$1,001 - $15,000",
                "party": "Democrat"
            },
            {
                "transaction_date": "11/29/2021",
                "asset_description": "Goldman Sachs Access Treasury 0-1 Year ETF",
                "asset_type": "Other Securities",
                "type": "Purchase",
                "amount": "$1,001 - $15,000",
                "party": "Democrat"
            }
          ],
        "1":[
            {
                "transaction_date": "11/29/2019",
                "asset_description": "Western Asset Inflation-Linked Opportunities & Inc",
                "asset_type": "Stock",
                "type": "Sale (Full)",
                "amount": "$1,001 - $15,000",
                "party": "Democrat"
            }
          ]
    }
  }

修改后的Python代码 #

import json

# 读取JSON文件
with open("xxxtester.json", "r") as f:
    data = json.load(f)

# 遍历transactions中的每个键值对
transactions = data["transactions"]
keys_to_delete = []

for key, transaction_list in transactions.items():
    # 筛选出2022年及以后的交易对象
    filtered_transactions = [
        tx for tx in transaction_list
        if int(tx["transaction_date"].split("/")[-1]) >= 2022
    ]
    if filtered_transactions:
        transactions[key] = filtered_transactions
    else:
        # 若筛选后列表为空，标记该键待删除
        keys_to_delete.append(key)

# 删除空列表对应的键
for key in keys_to_delete:
    del transactions[key]

# 写入修改后的JSON文件
with open("xxxtester.json", "w") as f:
    json.dump(data, f, indent=4)

代码关键说明 #

• 使用with语句读写文件，确保文件正确关闭
• 对每个交易对象，通过split("/")[-1]提取日期字符串中的年份部分，转为整数后判断是否≥2022
• 用列表推导式高效筛选符合条件的交易
• 处理后若某个交易列表为空，则删除对应的键（如示例中的"1"键）
• 最后用json.dump格式化输出JSON，保持缩进可读性

期望输出JSON #

{
    "transactions": {
        "0": [
            {
                "transaction_date": "11/29/2022",
                "asset_description": "Western Asset Inflation-Linked Opportunities & Inc",
                "asset_type": "Stock",
                "type": "Sale (Full)",
                "amount": "$1,001 - $15,000",
                "party": "Democrat"
            }
        ]
    }
}

内容的提问来源于stack exchange，提问作者kie_codes