最佳方式：Facebook JSON Parse to MongoDB (Python3)

Question

我正在尝试找出将 Facebook JSON 响应解析到 MongoDB 的最佳方法。

FB 事件 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"
}

有时事件没有上述所有字段，即：location 和 place 是可选的。

所以我做到了：

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 是我保存在 MongoDB 上的字典列表。

我的主要问题是：有没有更好的方法来代替很多 if-then-else 条件？

Answer 1

您可以将大部分 if 语句替换为 key: event.get("key", None) 或嵌套属性 val: event.get('key1', None).get('key2', None)

Answer 2

如果你想将 json 对象转换为 dict，那么就这样做：

import json

event_dict = json.loads(event)

Answer 3

要将所有内容转换为一级字典，您可以使用递归函数来遍历字典，并在出现键值对时提取它们。像这样的：

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)

这有点杂乱无章，但您应该能够根据自己的目的对其进行修改。

（这是针对python3的，对于python2，我认为您需要将dict.items（）替换为dict.iteritems（））

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。