SimpleJson handling of same named entities

2019-01-12 07:37发布

问题:

I'm using the Alchemy API in app engine so I'm using the simplejson library to parse responses. The problem is that the responses have entries that have the sme name

 {
    "status": "OK",
    "usage": "By accessing AlchemyAPI or using information generated by AlchemyAPI, you are agreeing to be bound by the AlchemyAPI Terms of Use: http://www.alchemyapi.com/company/terms.html",
    "url": "",
    "language": "english",
    "entities": [
        {
            "type": "Person",
            "relevance": "0.33",
            "count": "1",
            "text": "Michael Jordan",
            "disambiguated": {
                "name": "Michael Jordan",
                "subType": "Athlete",
                "subType": "AwardWinner",
                "subType": "BasketballPlayer",
                "subType": "HallOfFameInductee",
                "subType": "OlympicAthlete",
                "subType": "SportsLeagueAwardWinner",
                "subType": "FilmActor",
                "subType": "TVActor",
                "dbpedia": "http://dbpedia.org/resource/Michael_Jordan",
                "freebase": "http://rdf.freebase.com/ns/guid.9202a8c04000641f8000000000029161",
                "umbel": "http://umbel.org/umbel/ne/wikipedia/Michael_Jordan",
                "opencyc": "http://sw.opencyc.org/concept/Mx4rvViVq5wpEbGdrcN5Y29ycA",
                "yago": "http://mpii.de/yago/resource/Michael_Jordan"
            }
        }
    ]
}

So the problem is that the "subType" is repeated so the dict that a loads returns is just "TVActor" rather than a list. Is there anyway to go around this?

回答1:

The rfc 4627 that defines application/json says:

An object is an unordered collection of zero or more name/value pairs

And:

The names within an object SHOULD be unique.

It means that AlchemyAPI should not return multiple "subType" names inside the same object and claim that it is a JSON.

You could try to request the same in XML format (outputMode=xml) to avoid ambiguity in the results or to convert duplicate keys values into lists:

import simplejson as json
from collections import defaultdict

def multidict(ordered_pairs):
    """Convert duplicate keys values to lists."""
    # read all values into lists
    d = defaultdict(list)
    for k, v in ordered_pairs:
        d[k].append(v)

    # unpack lists that have only 1 item
    for k, v in d.items():
        if len(v) == 1:
            d[k] = v[0]
    return dict(d)

print json.JSONDecoder(object_pairs_hook=multidict).decode(text)

Example

text = """{
  "type": "Person",
  "subType": "Athlete",
  "subType": "AwardWinner"
}"""

Output

{u'subType': [u'Athlete', u'AwardWinner'], u'type': u'Person'}