HTTP Requests & APIs (requests)

An API lets your program talk to other programs over the internet — weather data, currency rates, your own backend. The requests library makes calling them feel as easy as calling a function.

Learn HTTP Requests & APIs (requests) in our free Python course — a beginner-friendly interactive lesson with runnable examples, a practice exercise and a…

Part of the free Python course at LearnCodingFast — hands-on lessons with examples you run in your browser, plus practice exercises and a quick quiz.

In this lesson you'll send GET and POST requests, read JSON responses, pass parameters and headers, and handle errors like a professional.

Every time you load a webpage, your browser sends an HTTP request to a server and gets a response back. Your Python program can do exactly the same thing — but instead of HTML, APIs usually return JSON data your code can use.

🌐 The four most common HTTP methods (verbs):

First, install the library (it's not built in):

A GET request fetches data. The response object gives you the status code, the raw text, and a handy .json() method:

response.json() is the bridge to the last lesson — it runs json.loads on the response body for you and hands back a normal Python dict or list.

Every response carries a status code. You only need to recognise the families:

Rather than checking codes by hand, let requests raise an exception on failure:

Most APIs accept parameters to filter or page results. Pass a dict to params= and requests builds the URL correctly (including escaping special characters):

To create something on a server, send a POST with a JSON body. The json= argument serializes your dict and sets the right header automatically:

Use json= for JSON bodies (the common case) and data= for form-encoded bodies (like an HTML form submission).

Networks fail. Servers go down. A professional request always has a timeout and a try/except around it:

This is what a clean, reusable API client looks like — parameters, headers, error handling and a tidy return value all in one place:

Notice how the messy nested JSON ( data["main"]["temp"] ) gets flattened into a clean dict the rest of your program can use without knowing the API's structure.

These lines fetch an API and print one field, but they're scrambled. Find the correct order:

Import, define the URL, make the request, check for errors before trusting the body, then parse and use it.

Success — a 200 status makes response.ok True (any 2xx code is OK).

json= — passing json=your_dict serializes it and sets the Content-Type to application/json. params= is for URL query strings; data= is for form-encoded bodies.

4xx — client error — 404 // 100 is 4, the "your mistake" family (resource not found).

Your programs can now talk to the whole internet!

You can send GET and POST requests, pass params and headers, read JSON responses, and handle timeouts and errors gracefully. APIs are how modern software connects — this skill opens thousands of doors.

🚀 Up next: Reading CSV & Excel Files — work with the spreadsheet data that runs the business world.

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