使用python更新字典值

Question

我有一个json文件，当使用json.loads()在python中加载该文件时，它会成为一个dictionary 。 JSON数据是一个nested dictionary可以包含一个'groups'内的另一个关键'groups'键。 'groups'键中的值是'name'键和'properties'键。

每个'properties'键都有一个唯一的'name'和'value'键。

我的目标是搜索'name'键值为"SportCar"的'groups'键，其'name' properties键的name键值为"BMW" ，只有在满足这些条件时，才更新'data'键，从'data':value1到'data':value2 。

json的示例如下

{
  "groups": [
    {
      "name": "SportCar",
      "properties": [
        {
          "name": "BMW",
          "value": {
            "type": "String",
            "encoding": "utf-8",
            "data": "value1"
          }
        },
        {
          "name": "Audi",
          "value": {
            "type": "Boolean",
            "data": true
          }
        }
      ],
      "groups": [
        {
          "name": "Trucks",
          "properties": [
            {
              "name": "Volvo",
              "value": {
                "type": "String",
                "encoding": "utf-8",
                "data": "value1"
              }
            }
          ]
        }
      ]
    },
    {
      "name": "MotorCycle",
      "properties": [
        {
          "name": "Yamaha",
          "value": {
            "type": "String",
            "encoding": "utf-8",
            "data": "value1"
          }
        }
      ],
      "groups": [
        {
          "name": "Speeders",
          "properties": [
            {
              "name": "prop2",
              "value": {
                "type": "String",
                "encoding": "utf-8",
                "data": "value1"
              }
            }
          ]
        }
      ]
    }
  ]
}

上面的json包含在myjson22.json中。 到目前为止，这是我尝试过的：

import json
from pprint import pprint

json_data=open('myjson22.json', 'r')
data = json.load(json_data)
#print(data)

def get_recursively(search_dict, field):
    """
    To read the json data as type dict and search all 'groups' keys for the 'name' key value value provided.
    """
    fields_found = []

    for key, value in search_dict.items():

        if key == field:
            fields_found.append(value)

        elif isinstance(value, dict):
            results = get_recursively(value, field)
            for result in results:
                fields_found.append(result)

        elif isinstance(value, list):
            for item in value:
                if isinstance(item, dict):
                    more_results = get_recursively(item, field)
                    for another_result in more_results:
                        fields_found.append(another_result)

    return fields_found
get_recursively(data, ["properties"][0])

输出为：

 [[{'name': 'BMW',
   'value': {'data': 'value1', 'encoding': 'utf-8', 'type': 'String'}},
  {'name': 'Audi', 'value': {'data': True, 'type': 'Boolean'}}],
 [{'name': 'Volvo',
   'value': {'data': 'value1', 'encoding': 'utf-8', 'type': 'String'}}],
 [{'name': 'Yamaha',
   'value': {'data': 'value1', 'encoding': 'utf-8', 'type': 'String'}}],
 [{'name': 'prop2',
   'value': {'data': 'value1', 'encoding': 'utf-8', 'type': 'String'}}]]

Answer 1

回溯是实现此递归解决方案的一种方法。 如果没有发现嵌套在根键中的'groups'键，则'name'键值与groups_name参数匹配，在本例中为“ SportCar”。 如果满足此条件，请检查同一'groups'键（即“ SportCar”键）， 'properties'键中的值，并将其'name'键值与properties_name参数（在本例中为“ BMW”）相匹配。 如果第二个条件也成立，则根据要求更新相同'properties'键中的'data'键值，否则返回（用于回溯）。

import json

json_data = open('myjson22.json', 'r')

data = json.load(json_data)

def get_recursively( myJson, groups_name, properties_name, value2):

    if 'groups' in myJson.keys():
        # As there are multiple values inside 'groups' key
        for jsonInsideGroupsKey in myJson['groups']:  
            get_recursively( jsonInsideGroupsKey, groups_name, properties_name, value2)

    if 'name' in myJson.keys():
        # check for groups name
        if myJson['name'] == groups_name:
            # check for properties name
            if myJson['properties'][0]['name'] == properties_name:
                # Update value. The changes will persist as we backtrack because
                # we are making the update at the original memory location
                # and not on a copy. For more info see deep and shallow copy.
                myJson['properties'][0]['value']['data'] = value2
    return

get_recursively(data,'SportCar','BMW','changedValue1')
get_recursively(data,'Speeders','prop2','changedValue2')
print data

我的输出：

{u'groups'：[{u'name'：u'SportCar'，u'groups'：[{u'name'：u'Trucks'，u'properties'：[{u'name'：u'Volvo '，u'value'：{u'data'：u'value1'，u'type'：u'String'，u'encoding'：u'utf-8'}}}}]，u'properties'： [{u'name'：u'BMW'，u'value'：{u'data'： 'changedValue1' ，u'type'：u'String'，u'encoding'：u'utf-8'}} ，{u'name'：u'Audi'，u'value'：{u'data'：True，u'type'：u'Boolean'}}]}，{u'name'：u'MotorCycle'， u'groups'：[{u'name'：u'Speeders'，u'properties'：[{u'name'：u'prop2'，u'value'：{u'data'： 'changedValue2' ，u 'type'：u'String'，u'encoding'：u'utf-8'}}}}]，u'properties'：[{u'name'：u'Yamaha'，u'value'：{u '数据'：u'value1'，u'类型'：u'String'，u'encoding'：u'utf-8'}}}}]}

美化为：

{
  "groups": [
    {
      "name": "SportCar",
      "properties": [
    {
      "name": "BMW",
      "value": {
        "type": "String",
        "encoding": "utf-8",
        "data": "ChangedValue1"
      }
    },
    {
      "name": "Audi",
      "value": {
        "type": "Boolean",
        "data": true
      }
    }
      ],
      "groups": [
    {
      "name": "Trucks",
      "properties": [
        {
          "name": "Volvo",
          "value": {
            "type": "String",
            "encoding": "utf-8",
            "data": "value1"
          }
        }
      ]
    }
      ]
    },
    {
      "name": "MotorCycle",
      "properties": [
    {
      "name": "Yamaha",
      "value": {
        "type": "String",
        "encoding": "utf-8",
        "data": "value1"
      }
    }
      ],
      "groups": [
    {
      "name": "Speeders",
      "properties": [
        {
          "name": "prop2",
          "value": {
            "type": "String",
            "encoding": "utf-8",
            "data": "ChangedValue2"
          }
        }
      ]
    }
      ]
    }
  ]
}