Question

我试图找出解析对MongoDB的Facebook JSON响应的最佳方法。

FB Event JSON：

{
  "description": "Event description",
  "name": "Event name",
  "place": {
    "name": "Place name",
    "location": {
      "city": "City",
      "country": "Country",
      "latitude": -26.31604,
      "longitude": -48.83667,
      "state": "State",
      "street": "Street address",
      "zip": "000000"
    },
    "id": "429579150543987"
  },
  "start_time": "2017-10-27T19:00:00-0200",
  "id": "1557095844358825"
}

有时，某个事件并未包含上述所有字段，即：location和place是可选的。

所以我做了：

event_dict = {
    'id': event['id'],
    'name': event['name'],
    'start_time': event['start_time']
}

if ("place" in event):
    if ("name" in event['place']):
        event_dict['place'] = event['place']['name']
    if ("location" in event['place']):
        if ("street" in event['place']['location']):
            event_dict['street'] = event['place']['location']['street']
        if ("zip" in event['place']['location']):
            event_dict['zip'] = event['place']['location']['zip']
        if ("city" in event['place']['location']):
            event_dict['city'] = event['place']['location']['city']
        if ("state" in event['place']['location']):
            event_dict['state'] = event['place']['location']['state']
        if ("country" in event['place']['location']):
            event_dict['country'] = event['place']['location']['country']

if ("end_time" in event):
    event_dict['end_time'] = event['end_time']

if ("description" in event):
    event_dict['description'] = event['description']

event_list.append(event_dict)

event_list是我在MongoDB上保存的词典列表。

我的主要问题是：是否有更好的方法来做，而不是很多if-then-else条件？

Answer 1

您可以使用key: event.get("key", None)或嵌套属性val: event.get('key1', None).get('key2', None)替换大部分if语句

Answer 2

如果要将json对象转换为dict，则只需执行：

import json

event_dict = json.loads(event)

Answer 3

要将所有内容转换为单级字典，您可以使用递归函数遍历字典，并在它们出现时提取键值对。像这样：

event = {
  "description": "Event description",
  "name": "Event name",
  "place": {
    "name": "Place name",
    "location": {
      "city": "City",
      "country": "Country",
      "latitude": -26.31604,
      "longitude": -48.83667,
      "state": "State",
      "street": "Street address",
      "zip": "000000"
    },
    "id": "429579150543987"
  },
  "start_time": "2017-10-27T19:00:00-0200",
  "id": "1557095844358825"
}


one_level_dict = {}

def recursive_extraction(dict, base_string = ""):
    for key, value in dict.items():
        if type(value) is type({}):
            recursive_extraction(value, base_string + key + "_")
        else:
            one_level_dict[base_string + key] = value

recursive_extraction(event)
print(one_level_dict)

这有点杂乱，但你应该能够根据你的目的修改它。

（这是针对python3的，对于python2，我认为你需要用dict.iteritems（）替换dict.items（））

编辑：添加了一个base_string来维护较低级别值的json结构的上下文。

最佳方式：Facebook JSON解析为MongoDB（Python3）

3 个答案: