我有一个json文件，使用json.loads()在python中加载时会成为dictionary。 json数据是nested dictionary，可以在另一个'groups'密钥中包含'groups'密钥。 'groups'密钥中的值是'name'密钥和'properties'密钥。
每个'properties'密钥都有一个唯一的'name'和一个'value'密钥。
我的目标是搜索'groups'密钥，其'name'密钥值为"SportCar"，其密钥值为properties name作为"BMW"，只有满足这些条件时，才能将'data'密钥从'data':value1更新为'data':value2。
json的一个例子如下
{
"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。这是我到目前为止所尝试的：
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])
，输出结果为：
[[{'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'}}]]
答案 0 :(得分：2)
实现这种递归解决方案的一种方法是使用回溯。如果找不到嵌套在根密钥中的'groups'个密钥，则'name'密钥值将与groups_name参数匹配，即＆＃39; SportCar＆＃39;在我们的例子中。如果满足此条件，请检查相同'groups'键内的值（即＆＃39; SportCar＆＃39;键＆＃39;} 'properties'键并匹配其'name'带有properties_name参数的键值（在我们的例子中是＆＃39; BMW＆＃39;）。如果第二个条件也为真，则根据要求更新同一'data'密钥中的'properties'密钥值，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＆＃39;群组＆＃39;：[{u＆＃39;姓名＆＃39;：你＆＃39; SportCar＆＃39;，你＆＃39;群组＆＃39;：[{你＆＃39;名称＆＃ 39;：你＆＃39;卡车＆＃39;，你的财产＆＃39;：[{u＆＃39;名称＆＃39;：你＆＃39;沃尔沃＆＃39;，你＆＃39;价值＆＃39;： {u＆＃39;数据＆＃39;：你＆＃39; value1＆＃39;，你＆＃39;键入＆＃39;：你＆＃39;字符串＆＃39;，你＆＃39;编码＆＃39;：你＆＃39; utf-8＆＃39;}}]}]，u＆＃39;属性＆＃39;：[{u＆＃39;名称＆＃39;：你＆＃39;宝马＆＃39;，你＆＃39;价值＆＃39;： {u＆＃39;数据＆＃39;：'changedValue1'，u＆＃39;键入＆＃39;：u＆＃39;字符串＆＃39;，u＆＃39;编码＆＃39;：u＆＃39; utf-8＆ ＃39;}}，{u＆＃39;姓名＆＃39;：你＆＃39;奥迪＆＃39;，你＆＃39;价值＆＃39;：{u＆＃39;数据＆＃39;：是的，你＆＃39;键入＆＃39;：u＆＃39;布尔＆＃39;}}}}，{u＆＃39;名称＆＃39;：你＆＃39; MotorCycle＆＃39;，你＆＃39; groups＆＃39;：[{u＆＃ 39;姓名＆＃39;：你＆＃39; Speeders＆＃39;，u＆＃39;属性＆＃39;：[{u＆＃39; name＆＃39 ;: u＆＃39; prop2＆＃39;，u＆＃39; value＆ ＃39;：{u＆＃39;数据＆＃39;：'changedValue2'，你＆＃39;键入＆＃39;：你＆＃39;字符串＆＃39;，u＆＃39;编码＆＃39;：你＆＃39; ; utf-8＆＃39;}}]}]，u＆＃39;属性＆＃39;：[{u＆＃39; name＆＃39 ;: u＆＃39; Yamaha＆＃39;，u＆＃39; value＆＃39; ：{u＆＃39;数据＆＃39;：你＆＃39; val ue1＆＃39;，你＆＃39;键入＆＃39;：你＆＃39;字符串＆＃39;，u＆＃39;编码＆＃39;：u＆＃39; utf-8＆＃39;}}]}]}
美化它看起来像：
{
"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"
}
}
]
}
]
}
]
}