如何使用字典从python中提取嵌套的JSON值？

Question

My database is formatted like this:

{
  "latitude" : 41.884629,
  "longitude" : -87.648764,
  "name" : "Bar Siena",
  "placeID" : "ChIJf3h_t9osDogReehZO7Hgk50",
  "vibes" : {
    "LGpswrvLgfYppcBG4bpmNzXQVoU2" : {
      "rating" : 1,
      "timestamp" : 1.477961061358844E9
    },
    "OSzA2KhTBWS3pxVnCZ6eScAuNDG3" : {
      "rating" : 5,
      "timestamp" : 1.477955566836665E9
    }
  }
}

I want to pull both the names of each bar, and every rating corresponding to it in the vibes table. My code looks like this:

firebase = pyrebase.initialize_app(config)

db = firebase.database()
for i in range(1,100):
    venues = db.child("venues").child(i).get()
    dict = (venues.val())
    print(dict['name'])

So far i'm only able to get the names, but i'm not sure how to go deeper and get the ratings. My database is managed using Firebase, and I'm using a python library called Pyrebase that's just a wrapper for the javascript api. I'm having trouble because each vibe has a generated hash key so i'm not sure how to go deeper. Any thoughts?

Answer 1

vibes probably comes as a dictionary. What you want are the ratings of each hash key, so you can do something like

for hashkey, vibe_dict in dict['vibes'].items(): # dict is a Python keyword, so it's a bad choice for a variable!
    print(hashkey, vibe_dict['rating'])

Answer 2

I am not sure about firebase , but in plain python you may do it like:

>>> for vibe in my_json['vibes'].values():
...     print vibe['rating']
...
1  # Rating of item 1
5  # Rating of item 2

where my_json is the dict build from your json:

{
   "latitude":41.884629,
   "longitude":-87.648764,
   "name":"Bar Siena",
   "placeID":"ChIJf3h_t9osDogReehZO7Hgk50",
   "vibes":{
      "LGpswrvLgfYppcBG4bpmNzXQVoU2":{
         "rating":1,
         "timestamp":1.477961061358844E9
      },
      "OSzA2KhTBWS3pxVnCZ6eScAuNDG3":{
         "rating":5,
         "timestamp":1.477955566836665E9
      }
   }
}

Answer 3

If your venues variable is a JSON-like object as in example, you can use the standart json library to work with it:

import json
dict_data = json.loads(venues)
print dict_data['latitude']

Btw, it's a bad style of development - to overwrite built-in Python funuctions. In your example you're overwriting dict(dict is a default Python type-object)