Working with structured data

Introduction to APIs in Python

Chris Ramakers

Engineering manager

Complex data structures

Lyric API response

Lyric API response with HTTP 200 OK. Headers: Content-Type: plain/text, Content-Language: en-US, Last-Modified: Wed, 21 Oct 2023. Body: lyrics from "Problem Child" by AC/DC.

Album API response

Album API response with HTTP 200 OK. Headers specify JSON content. The body includes album details for "Back in Black" by AC/DC, listing track titles.

Introduction to APIs in Python

Complex data structures: JSON

  • JSON
    • JavaScript Object Notation
    • Widely supported
    • Human readable & machine usable
  • Content-type, mime-type or media-type
  • Other formats
    • XML
    • CSV
    • YAML

Album API response

Album API response with HTTP 200 OK. Headers specify JSON content. The body includes album details for "Back in Black" by AC/DC, listing track titles.

Introduction to APIs in Python

From Python to JSON and back

  A visual representation of encoding and decoding JSON formatted text using Python. The JSON contains album details for "Back in Black" by AC/DC.

import json
album =  {'id': 42, 'title':"Back in Black"}
string = json.dumps(album) # Encodes a python object to a JSON string
album = json.loads(string) # Decodes a JSON string to a Python object
Introduction to APIs in Python

Requesting JSON data

# GET request without headers
response = requests.get('http://api.music-catalog.com/lyrics')
print(response.text)

N' I never miss Cause I'm a problem child - AC/DC, Problem Child

# GET request with an accept header
response = requests.get('http://api.music-catalog.com/lyrics', headers={'accept': 'application/json'})

# Print the JSON text
print(response.text)


# Decode into a Python object
data = response.json()
print(data['artist'])

{'artist': 'AC/DC', 'lyric': "N' I never miss Cause I'm a problem child", 'track': 'Problem Child'}

AC/DC
Introduction to APIs in Python

Sending JSON data

import requests
playlist = {"name": "Road trip", "genre":"rock", "private":"true"}

# Add the playlist using via the `json` argument 
response = requests.post("http://api.music-catalog.com/playlists", json=playlist)

# Get the request object
request = response.request

# Print the request content-type header
print(request.headers['content-type'])

application/json
Introduction to APIs in Python

Let's practice!

Introduction to APIs in Python

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