通过嵌套json递归迭代python中的特定键
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recursive iteration through nested json for specific key in python
提问by adam
I'm trying to pull nested values from a json file. I want to print out each of the values for every "id" key. I think I'm close but can't figure out why the obj type changes from a dict to a list, and then why I'm unable to parse that list. Here is a link to the json I'm working with: http://hastebin.com/ratevimixa.tex
我正在尝试从 json 文件中提取嵌套值。我想打印出每个“id”键的每个值。我想我很接近但无法弄清楚为什么 obj 类型从 dict 更改为列表，然后为什么我无法解析该列表。这是我正在使用的 json 的链接：http: //hastebin.com/ratevimixa.tex
and here is my current code:
这是我当前的代码：
#!/usr/bin/env python
#-*- coding: utf-8 -*-
import json
json_data = open('JubJubProductions.json', 'r+')
jdata = json.loads(json_data.read().decode("utf-8"))
def recursion(dict):
for key, value in dict.items():
if type(value) == type(dict):
if key != "paging":
for key, value in value.items():
if isinstance (value,list):
print key
# place where I need to enter list comprehension?
if type(value) == type(dict):
if key == "id":
print " id found " + value
if key != "id":
print key + " 1st level"
if key == "id":
print key
else:
if key == "id":
print "id found " + value
if __name__ == '__main__':
recursion(jdata)
-------------------------------------------------------------------------------------------update
-------------------------------------------------- -----------------------------------------更新
This is now what I'm working with and it'll return a single id value, but not all of them:
这就是我现在正在使用的，它将返回一个 id 值，但不是全部：
#!/usr/bin/env python
#-*- coding: utf-8 -*-
import json
json_data = open('jubjubProductions', 'r+')
jdata = json.loads(json_data.read().decode("utf-8"))
def id_generator(d):
for k, v in d.items():
if k == "id":
yield v
elif isinstance(v, dict):
for id_val in id_generator(v):
yield id_val
if __name__ == '__main__':
for _ in id_generator(jdata):
print (_)
采纳答案by Filip Malczak
def id_generator(dict_var):
for k, v in dict_var.items():
if k == "id":
yield v
elif isinstance(v, dict):
for id_val in id_generator(v):
yield id_val
This will create an iterator which will yield every value on any level under key "id". Example usage (printing all of those values):
这将创建一个迭代器，它将产生键“id”下任何级别的每个值。示例用法（打印所有这些值）：
for _ in id_generator(some_json_dict):
print(_)
回答by Bo Sunesen
The JSON might contain a list of objects, which needs to be searched:
JSON 可能包含需要搜索的对象列表：
Python 2.7 version:
Python 2.7 版本：
def item_generator(json_input, lookup_key):
if isinstance(json_input, dict):
for k, v in json_input.iteritems():
if k == lookup_key:
yield v
else:
for child_val in item_generator(v, lookup_key):
yield child_val
elif isinstance(json_input, list):
for item in json_input:
for item_val in item_generator(item, lookup_key):
yield item_val
Python 3.x version:
Python 3.x 版本：
def item_generator(json_input, lookup_key):
if isinstance(json_input, dict):
for k, v in json_input.items():
if k == lookup_key:
yield v
else:
yield from item_generator(v, lookup_key)
elif isinstance(json_input, list):
for item in json_input:
yield from item_generator(item, lookup_key)
