🦉 Module 10

Connecting to an API

Your programs can ask the internet for live data. An API is like owl post for computers.

A mechanical pigeon carries a glowing data capsule between a brass computer and a cloud library. — Rowan sent a request into the wide web. The dragon is waiting for the response in strict loaf position.

🪄 The concept

An API is a service that returns data (often JSON) when you request a URL. The requests library helps you get that data in Python (pip install requests).

Check status_code == 200 (OK), then .json() turns the response into dicts and lists you already know how to loop.

Nested JSON is just nested dictionaries/lists — walk key by key, then loop when you hit a list of results.

💬 Discussion

Talk these through with a friend, a class, or just your notes app:

What live data would make a school project cooler? (weather, space station location, trivia…)
Why check status codes instead of assuming every request works?
Is data from the internet always trustworthy? What would you double-check?

💻 Code walkthrough

Copy into your editor, or download the .py file and run it. Tinker — change names, numbers, and spells.

Fetching JSON from an API (pip install requests) advice_api.py

import requests

# APIs return live data — here we ask a free “advice” service for a quote
url = "https://api.adviceslip.com/advice"
response = requests.get(url)

# Check status — 200 means OK
if response.status_code == 200:
    data = response.json()          # parse JSON into a Python dict
    print("Hermione says:", data["slip"]["advice"])
else:
    print("Could not reach the owl post:", response.status_code)

Working with nested JSON working_with_nested_json.py

# Many APIs nest data — use keys step by step
# Example structure (your real API may look different):
iss_position = {
    "iss_position": {"latitude": "45.1234", "longitude": "-75.5678"},
    "timestamp": 1710000000
}

lat = iss_position["iss_position"]["latitude"]
lon = iss_position["iss_position"]["longitude"]
print("International Space Station near:", lat, lon)

Loop through a list inside JSON loop_through_a_list_inside_json.py

# Many APIs return a list of objects — loop and print each one
# (sample data — real API responses look similar)
trivia = {
    "results": [
        {"question": "What is the counter-spell to Lumos?", "answer": "Nox"},
        {"question": "Who teaches Transfiguration?", "answer": "McGonagall"}
    ]
}

for item in trivia["results"]:
    print("Q:", item["question"])
    print("A:", item["answer"])
    print("---")

Cat facts API (no API key required) cat_fact.py

import requests

url = "https://catfact.ninja/fact"
response = requests.get(url, timeout=10)

if response.status_code == 200:
    fact = response.json()
    print("Did you know?")
    print(fact["fact"])
else:
    print("Could not fetch fact:", response.status_code)

🧪 Try this

Run advice_api.py three times. Did the advice change?
Run cat_fact.py, then change the print message to sound like a Hogwarts librarian announcing the fact.
Browse a public API list (linked on the course page) and sketch which keys you would dig into first.

📁 Local files

All runnable Python for this module:

module-10-apis/ · all modules

🎬 Video lesson

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