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STUDENT NOTES · DAY 15 OF 24
Talking to the Internet 🌐
Weather, cricket scores, memes — the internet is full of data. An API is the polite way for YOUR code to ask for it.
1What is an API?
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Py: An API is a restaurant menu for programs: the service says "here's what you can ask for and how" — your code orders, the server delivers.
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Bittu: I ask the weather API for Pune. It answers in 0.2 seconds. No umbrella needed for negotiations.
2requests.get — placing the order
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Professor Hoot: Status codes: 200 = OK ✅, 404 = not found 🤷, 500 = server having a bad day 🔥. Learn the big three.
3JSON — the language servers speak
Servers reply in JSON — which looks almost exactly like Python dicts and lists! .json() converts it:
Pretend Weather API — pick a city!
…press a city to send the request…
4Keep your key secret! 🔑
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Bugly: Post your API key on GitHub and strangers will use YOUR quota within minutes. Hehehe. I love careless coders.
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Py: Treat keys like ATM PINs: never share, never paste in public code. We'll use environment variables in class.
5Quick quiz! 🧠
The server replies with status 404. Meaning?
💡 200 OK, 404 not found, 500 server error — the holy trinity of status codes.
r = requests.get(url). How do you turn the JSON reply into Python data?
💡 .json() parses the reply into dicts and lists you can use immediately.
6Your mission 🚀
Mission 1: In class-shared code, call the weather API for YOUR city and print the temperature.
Mission 2: Print the status code. Then break the URL on purpose and see what code you get.
Mission 3: Explore the JSON reply: print data.keys() to see what else the server sent you.
Day 15 done — the internet answers you now! 🌐
Next: put it all together — build a real Weather App.
Go to Day 16: Weather App →