如何按键查找特定的 JSON 值

发布于12月27日

There is a JSON like this:

{
  "P1": "ss",
  "Id": 1234,
  "P2": {
      "P1": "cccc"
  },
  "P3": [
      {
          "P1": "aaa"
      }
  ]
}

How can I find all P1's value without it iterating all JSON?

P.S.: P1 can be anywhere in the JSON.

If no method can do this, can you tell me how to iterate through the JSON?

推荐答案

My approach to this problem would be different.

由于JSON不允许深度优先搜索，因此将JSON转换为Python对象，将其提供给XML解码器，然后提取要搜索的 node

from xml.dom.minidom import parseString
import json        
def bar(somejson, key):
    def val(node):
        # Searches for the next Element Node containing Value
        e = node.nextSibling
        while e and e.nodeType != e.ELEMENT_NODE:
            e = e.nextSibling
        return (e.getElementsByTagName('string')[0].firstChild.nodeValue if e 
                else None)
    # parse the JSON as XML
    foo_dom = parseString(xmlrpclib.dumps((json.loads(somejson),)))
    # and then search all the name tags which are P1's
    # and use the val user function to get the value
    return [val(node) for node in foo_dom.getElementsByTagName('name') 
            if node.firstChild.nodeValue in key]

bar(foo, 'P1')
[u'cccc', u'aaa', u'ss']
bar(foo, ('P1','P2'))
[u'cccc', u'cccc', u'aaa', u'ss']