Python12 min read

Python Async/Await: Modern Asynchronous Programming

Master async/await in Python. Learn how to write asynchronous code that's fast and efficient. Perfect for web scraping, API calls, and I/O operations. This is how modern Python handles concurrency.

David Kim

December 18, 2025

0.0k0

Async/await in Python lets you write code that can do multiple things at once without blocking. Perfect for web requests, file I/O, or any operation where you're waiting for something.

Why Async?

When your code makes a network request or reads a file, it waits. With async, while one request is waiting, your code can handle other requests. This makes your programs much faster.

The Basics

The async keyword makes a function a coroutine, and await pauses execution until something completes. It's similar to JavaScript's async/await if you know that. The syntax is clean and easy to read.

Running Async Code

You need an event loop to run async code. I'll show you how to use asyncio.run() and how to create tasks that run concurrently.

Real Examples

I'll show you practical examples - making multiple API calls, reading files concurrently, building async web scrapers. These are real patterns you'll use.

#Python#Async#Await#Asyncio#Concurrency

Common Questions & Answers

How do I write an async function in Python?

Use the `async` keyword before `def`. Inside, use `await` to wait for async operations. Call async functions with `await` or use `asyncio.run()` to execute them.

python

Run Explain

import asyncio

async def fetch_data(url):
    # Simulate network request
    await asyncio.sleep(1)
    return f"Data from {url}"

async def main():
    data = await fetch_data("https://api.example.com")
    print(data)

# Run the async function
asyncio.run(main())

How do I run multiple async functions concurrently?

Use asyncio.gather() to run multiple coroutines at the same time. They'll all start together and wait for all to complete. This is much faster than running them one by one.