What are some examples of using asyncio in Python?

What are some examples of using asyncio in Python?

Asyncio is a library in Python used for writing concurrent code using the async/await syntax. Here are a few examples:

1. Basic Async Function: You can define an async function using async def and call it with await.
2. Running Multiple Tasks: Use asyncio.gather() to run multiple async functions concurrently.
3. Web Scraping: Asyncio can be used with libraries like aiohttp to scrape web pages asynchronously.

Can you show me a code snippet for running multiple tasks?

Sure! Here's a simple example:

import asyncio

async def task(name, delay):
    print(f'Task {name} starting')
    await asyncio.sleep(delay)
    print(f'Task {name} completed')

async def main():
    await asyncio.gather(
        task('A', 2),
        task('B', 1),
        task('C', 3)
    )

asyncio.run(main())

This code runs three tasks concurrently, each with a different delay.

What libraries work well with asyncio?

Some popular libraries that work well with asyncio include:

• aiohttp: For making asynchronous HTTP requests.
• aiomysql: For asynchronous MySQL database access.
• asyncpg: For asynchronous PostgreSQL database access.
• websockets: For building WebSocket servers and clients.

How does error handling work in asyncio?

Error handling in asyncio can be done using try/except blocks within your async functions. If an exception occurs in one of the tasks, it can be caught and handled appropriately. You can also use asyncio.gather() with the return_exceptions=True argument to collect exceptions without stopping the execution of other tasks.