How does async/await work in Python?

Python's async/await syntax enables asynchronous programming by allowing functions to pause execution while waiting for I/O operations, enabling concurrent handling of thousands of operations without threading overhead.

Understanding Async Functions

An async function is defined with 'async def' and returns a coroutine object. The 'await' keyword pauses the coroutine until the awaited operation completes, allowing other coroutines to run. This is managed by an event loop, typically asyncio.

When to Use Async Python

Use async for I/O-bound operations: HTTP requests, database queries, file operations, and WebSocket connections. Async provides no benefit for CPU-bound tasks like mathematical computations or image processing.

Frequently Asked Questions

Is async faster than threading in Python?

For I/O-bound tasks, async is typically faster and more memory-efficient than threading because it avoids thread creation overhead and GIL contention. A single async process can handle thousands of concurrent connections.

Can I mix sync and async code?

Yes, use asyncio.run() to call async code from sync code, or run_in_executor() to call blocking sync code from async code without blocking the event loop.