Getting data with requests

API endpoints

Our first port of call should be the documentation - take a look around the sections in the API Endpoint Reference.

You'll discover:

• the base_url for the API is https://api.spotify.com/v1

• various endpoints which accept GET requests, such as:

  https://api.spotify.com/v1/recommendations
https://api.spotify.com/v1/artists/{id}

Looking at the detailed page of each of these endpoints, you'll see a list of the query parameters that can (or are required) be provided, as well as the need for authorization details to be provided in the header.

Again, requests will simplify this process for us.

Using requests.get()

We previously covered how REST APIs typically support GET requests, which can be used to retrieve data from the API.

repl.it code snippet

Code walkthrough

Let's go through main.py and see what happened...

Authorization headers

import requests

#replace this with your current client_credentials access_token:
access_token = 'BQDNokgFn6wBLEpB1NPe-dhG4g29OWnLCPrRZGZvZ-ZlRHGPsi51els1Thy5lARaGkHVikTu4D9gB9XUeus' 

headers = {'Authorization': f'Bearer {access_token}'}

• we imported requests and assigned our token to access_token
• we created a headers dictionary, with this parameter:value pair:
  Authorization: Bearer [access_token]

Notice that we had to do some work to get the value in the format the API requires (with Bearer before the access_token); this is mentioned in the API documentation but wasn't clear to me before Google came to the rescue.

URL components

base_url = 'https://api.spotify.com/v1'
endpoint = '/tracks/'
identifier = '7azo4rpSUh8nXgtonC6Pkq'
full_url = f'{base_url}{endpoint}{identifier}'

• the URL is in component parts and combined using an f-string; this will allow us to make further requests to different endpoints more easily

• the identifier value is a track_id; you can get these from the Spotify Web Player:

  • right-click on any song title
  • click Share then Copy Song Link
  • the track_id is the final part of the URL

Response data

response = requests.get(full_url, headers=headers)
data = response.json()

print(list(data.keys()), '\n\n', data['name'])

['album', 'artists', 'available_markets', 'disc_number', 'duration_ms', 'explicit', 'external_ids', 'external_urls', 'href', 'id', 'is_local', 'name', 'popularity', 'preview_url', 'track_number', 'type', 'uri']

 Thriller

• we used the .json() method on the Response object to convert the JSON data into equivalent Python data stuctures
• we took a look at the list of .keys() in the resulting dictionary
• we fished out the value for the name key from the dictionary

JSON structure

We learned previously how JSON is made up of the following structures:

• JSON objects, which get converted to Python dictionaries
• JSON arrays, which get converted to Python lists

JSON datasets are often heavily nested; by this it's meant that we can expect to encounter instances of these data structures within others.

Example of JSON structure

data['artists']

    [{'external_urls': {'spotify': 'https://open.spotify.com/artist/3fMbdgg4jU18AjLCKBhRSm'},
      'href': 'https://api.spotify.com/v1/artists/3fMbdgg4jU18AjLCKBhRSm',
      'id': '3fMbdgg4jU18AjLCKBhRSm',
      'name': 'Michael Jackson',
      'type': 'artist',
      'uri': 'spotify:artist:3fMbdgg4jU18AjLCKBhRSm'}]

data['artists'][0]['name']

    'Michael Jackson'

• the value associated with the data key is itself a list of dictionaries (in this case there is only one element in the list, but the structure means that several artists could be accomodated)

print(data['artists'][0]['external_urls']['spotify'])

    https://open.spotify.com/artist/3fMbdgg4jU18AjLCKBhRSm

• to extract the Spotify URL we are getting a value from a dictionary, which is itself a value in another dictionary, which is itself an element in a list, which is itself a value in another dictionary. Phew!

The repl.it console

After running the repl you forked earlier, you can access the data dictionary via the console:

• after running main.py, the data dictionary (and anything else imported or created) is in memory
• as a Python repl, the Python interpreter is already running, and we can enter Python commands