如何使用Python根据嵌套Key路径修改JSON文件指定值？

我需要用Python实现根据给定的嵌套Key路径（比如["payload","ServiceConfiguration", "TokenSettings", "ClientId"]）修改JSON文件里的对应值。目前已经能用直接链式索引（比如superHeroSquad['payload']['ServiceConfiguration']['TokenSettings']['ClientId'] = "text"）完成修改，但没法通过Key路径数组的方式实现。我尝试写递归方法但没成功，计划的实现步骤是：

• 方法1接收Key路径数组和文件名两个参数
• 把JSON文件内容加载成Python字典
• 调用递归方法，传入目标Key和字典，递归遍历直到定位到下游目标Key并更新其值

相关JSON示例 #

{
  "payloadFormatVersion": "9.0",
  "payload": {
    "ServiceConfiguration": {
      "LoggingSettings": {
        "NumberOfLogFilesToKeep": 7,
        "LogFileSizeBytes": 0,
        "LogFolderPath": "C:\\demo\\logs\\feature\\",
        "EnvironmentType": "testingenv",
        "DataRelayLogSink": {
          "PeriodInSeconds": 60,
          "TargetAddress": "http://localhost:portNumber/dumm1",
          "TargetTokenAddress": "http://localhost:portnumber/token",
          "PayloadType": "somedata",
          "TokenCredentials": {
            "ClientId": "testclientid",
            "ClientSecret": "testclientsecret",
            "GrantType": "testgranttype"
          }
        }
      }
    }
  }
}

现有尝试的代码片段 #

def repalcejsonForSpecificKey(keyPath,fileName):
    filePath = "C:\\rajesh\\Configurations\\" + fileName + "\\" + fileName + ".json"
    print(filePath)
    Dict = {}
    with open(filePath) as f:
        superHeroSquad = json.load(f)
        duplicatedict={}
        duplicatedict=superHeroSquad
        testDict=getDictonaryItems(keyPath[0],**superHeroSquad)
        print(testDict)

def getDictonaryItems(searchKey, duplicatedict):
        if searchKey in duplicatedict.keys():
            testDict = duplicatedict[searchKey]
        return testDict

keyPath = ["payload","ServiceConfiguration", "TokenSettings", "ClientId"]
fileName="vestas.sdh.dr.gateway"
repalcejsonForSpecificKey(keyPath,fileName)

解决方案 #

现有代码仅处理了Key路径的第一个元素，未实现完整的路径遍历和值更新逻辑，以下提供两种可行实现方式：

方式1：迭代遍历实现（更直观） #

通过迭代逐步定位到目标Key的父节点，最后修改目标值：

import json

def replace_json_value(key_path, file_name, new_value):
    # 构建文件路径
    file_path = f"C:\\rajesh\\Configurations\\{file_name}\\{file_name}.json"
    
    # 加载JSON为字典
    with open(file_path, 'r') as f:
        data = json.load(f)
    
    # 遍历路径直到倒数第二个Key，定位父节点
    current_node = data
    for key in key_path[:-1]:
        if key not in current_node:
            raise ValueError(f"路径中的Key '{key}'不存在")
        current_node = current_node[key]
    
    # 更新目标Key的值
    target_key = key_path[-1]
    if target_key not in current_node:
        raise ValueError(f"目标Key '{target_key}'不存在")
    current_node[target_key] = new_value
    
    # 写回修改后的JSON文件
    with open(file_path, 'w') as f:
        json.dump(data, f, indent=4)

# 使用示例（注意对应实际JSON结构修正路径）
key_path = ["payload","ServiceConfiguration", "LoggingSettings", "DataRelayLogSink", "TokenCredentials", "ClientId"]
file_name = "vestas.sdh.dr.gateway"
replace_json_value(key_path, file_name, "new_client_id_123")

方式2：递归遍历实现 #

按计划通过递归完成路径遍历和值更新：

import json

def traverse_update(current_data, key_path, new_value, index=0):
    if index == len(key_path) - 1:
        # 到达目标Key，执行更新
        if key_path[index] not in current_data:
            raise ValueError(f"目标Key '{key_path[index]}'不存在")
        current_data[key_path[index]] = new_value
        return
    # 递归进入下一层节点
    next_key = key_path[index]
    if next_key not in current_data:
        raise ValueError(f"路径中的Key '{next_key}'不存在")
    traverse_update(current_data[next_key], key_path, new_value, index + 1)

def replace_json_value_recursive(key_path, file_name, new_value):
    file_path = f"C:\\rajesh\\Configurations\\{file_name}\\{file_name}.json"
    
    with open(file_path, 'r') as f:
        data = json.load(f)
    
    traverse_update(data, key_path, new_value)
    
    # 写回文件
    with open(file_path, 'w') as f:
        json.dump(data, f, indent=4)

# 使用示例
key_path = ["payload","ServiceConfiguration", "LoggingSettings", "DataRelayLogSink", "TokenCredentials", "ClientId"]
file_name = "vestas.sdh.dr.gateway"
replace_json_value_recursive(key_path, file_name, "recursive_new_client_id")

注意事项 #

• 注意Key路径的准确性：示例JSON中不存在TokenSettings，实际有效路径需对应JSON结构调整
• 写回文件时添加indent=4可保持JSON格式的可读性
• 代码中加入了Key不存在的异常处理，避免程序无提示崩溃

内容的提问来源于stack exchange，提问作者rajesh