Module 3: Concurrency & AsyncIO

3.1 Threading vs Multiprocessing

Python offers two main ways to achieve parallelism:

• Threading: Good for I/O-bound tasks. Limited by the Global Interpreter Lock (GIL).
• Multiprocessing: Good for CPU-bound tasks. Bypasses the GIL by creating separate processes.

3.2 The `asyncio` Library

asyncio is a library to write concurrent code using the async/await syntax. It is used as a foundation for multiple Python asynchronous frameworks (like FastAPI).

import asyncio

async def main():
    print('Hello ...')
    await asyncio.sleep(1)
    print('... World!')

asyncio.run(main())

3.3 Event Loops and Coroutines

The event loop is the core of every asyncio application. It runs asynchronous tasks and callbacks, performs network IO operations, and runs subprocesses.