扁平化一个字典

Question

我有以下数组(只有一个dict):

[{
    'RuntimeInMinutes': '21',
    'EpisodeNumber': '21',
    'Genres': ['Animation'],
    'ReleaseDate': '2005-02-05',
    'LanguageOfMetadata': 'EN',
    'Languages': [{
        '_Key': 'CC',
        'Value': ['en']
    }, {
        '_Key': 'Primary',
        'Value': ['EN']
    }],
    'Products': [{
        'URL': 'http://www.hulu.com/watch/217566',
        'Rating': 'TV-Y',
        'Currency': 'USD',
        'SUBSCRIPTION': '0.00',
        '_Key': 'US'
    }, {
        'URL': 'http://www.hulu.com/d/217566',
        'Rating': 'TV-Y',
        'Currency': 'USD',
        'SUBSCRIPTION': '0.00',
        '_Key': 'DE'
    }],
    'ReleaseYear': '2005',
    'TVSeriesID': '5638#TVSeries',
    'Type': 'TVEpisode',
    'Studio': '4K Media'
}]

我想把这个字母弄平如下:

[{
    'RuntimeInMinutes': '21',
    'EpisodeNumber': '21',
    'Genres': ['Animation'],
    'ReleaseDate': '2005-02-05',
    'LanguageOfMetadata': 'EN',
    'Languages._Key': ['CC', 'Primary'],
    'Languages.Value': ['en', 'EN'],
    'Products.URL': ['http://www.hulu.com/watch/217566', 'http://www.hulu.com/d/217566'],
    'Products.Rating': ['TV-Y', 'TV-Y'],
    'Products.Currency': ['USD', 'USD'],
    'Products.SUBSCRIPTION': ['0.00', '0.00'],
    'Products._Key': ['US', 'DE'],
    'ReleaseYear': '2005',
    'TVSeriesID': '5638#TVSeries',
    'Type': 'TVEpisode',
    'Studio': '4K Media'
}]

换句话说,无论何时遇到dict,都需要转换为字符串,数字或列表.

我目前所拥有的是下面的内容,它使用while循环遍历json的所有子路径.

    while True:

        for key in copy(keys):

            val = get_sub_object_from_path(obj, key)

            if isinstance(val, dict):
                FLAT_OBJ[key.replace('/', '.')] = val
            else:
                keys.extend(os.path.join(key, _nextkey) for _nextkey in val.keys())
            keys.remove(key)

        if (not keys) or (n > 5):
            break
        else:
            n += 1
            continue

Answer 1

您可以使用生成器的递归:

from collections import defaultdict
_d = [{'RuntimeInMinutes': '21', 'EpisodeNumber': '21', 'Genres': ['Animation'], 'ReleaseDate': '2005-02-05', 'LanguageOfMetadata': 'EN', 'Languages': [{'_Key': 'CC', 'Value': ['en']}, {'_Key': 'Primary', 'Value': ['EN']}], 'Products': [{'URL': 'http://www.hulu.com/watch/217566', 'Rating': 'TV-Y', 'Currency': 'USD', 'SUBSCRIPTION': '0.00', '_Key': 'US'}, {'URL': 'http://www.hulu.com/d/217566', 'Rating': 'TV-Y', 'Currency': 'USD', 'SUBSCRIPTION': '0.00', '_Key': 'DE'}], 'ReleaseYear': '2005', 'TVSeriesID': '5638#TVSeries', 'Type': 'TVEpisode', 'Studio': '4K Media'}]

def get_vals(d, _path = []):
  for a, b in getattr(d, 'items', lambda :{})():
    if isinstance(b, list) and all(isinstance(i, dict) or isinstance(i, list) for i in b):
       for c in b:
         yield from get_vals(c, _path+[a])
    elif isinstance(b, dict):
       yield from get_vals(b, _path+[a])
    else:
       yield ['.'.join(_path+[a]), b]

results = [i for b in _d for i in get_vals(b)]
_c = defaultdict(list)
for a, b in results:
  _c[a].append(b)

result = [{a:list(b) if len(b) > 1 else b[0] for a, b in _c.items()}]
import json
print(json.dumps(result, indent=4))

输出:

[
  {
    "RuntimeInMinutes": "21",
    "EpisodeNumber": "21",
    "Genres": [
        "Animation"
    ],
    "ReleaseDate": "2005-02-05",
    "LanguageOfMetadata": "EN",
    "Languages._Key": [
        "CC",
        "Primary"
    ],
    "Languages.Value": [
        [
            "en"
        ],
        [
            "EN"
        ]
    ],
    "Products.URL": [
        "http://www.hulu.com/watch/217566",
        "http://www.hulu.com/d/217566"
    ],
    "Products.Rating": [
        "TV-Y",
        "TV-Y"
    ],
    "Products.Currency": [
        "USD",
        "USD"
    ],
    "Products.SUBSCRIPTION": [
        "0.00",
        "0.00"
    ],
    "Products._Key": [
        "US",
        "DE"
    ],
    "ReleaseYear": "2005",
    "TVSeriesID": "5638#TVSeries",
    "Type": "TVEpisode",
    "Studio": "4K Media"
  }
]

编辑:外部函数包装解决方案:

def flatten_obj(data):
  def get_vals(d, _path = []):
    for a, b in getattr(d, 'items', lambda :{})():
      if isinstance(b, list) and all(isinstance(i, dict) or isinstance(i, list) for i in b):
        for c in b:
          yield from get_vals(c, _path+[a])
      elif isinstance(b, dict):
        yield from get_vals(b, _path+[a])
      else:
        yield ['.'.join(_path+[a]), b]
  results = [i for b in data for i in get_vals(b)]
  _c = defaultdict(list)
  for a, b in results:
     _c[a].append(b)
  return [{a:list(b) if len(b) > 1 else b[0] for a, b in _c.items()}]