Async Python Patterns

Quick Start

import asyncio

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

asyncio.run(main())

When To Use

• Building async web APIs (FastAPI, aiohttp)
• Implementing concurrent I/O operations
• Creating web scrapers with concurrent requests
• Developing real-time applications (WebSockets)
• Processing multiple independent tasks simultaneously
• Building microservices with async communication

When NOT To Use

• CPU-bound optimization - use python-performance instead
• Testing async code - use python-testing async module

Modules

• See

  modules/basic-patterns.md

  - Core async/await, gather(), and task management
• See

  modules/concurrency-control.md

  - Semaphores and locks for rate limiting
• See

  modules/error-handling-timeouts.md

  - Error handling, timeouts, and cancellation
• See

  modules/advanced-patterns.md

  - Context managers, iterators, producer-consumer
• See

  modules/testing-async.md

  - Testing with pytest-asyncio
• See

  modules/real-world-applications.md

  - Web scraping and database operations
• See

  modules/pitfalls-best-practices.md

  - Common mistakes and best practices

Exit Criteria

• Async patterns applied correctly
• No blocking operations in async code
• Proper error handling implemented
• Rate limiting configured where needed
• Tests pass with pytest-asyncio

Troubleshooting

Common Issues

asyncio.run()

get_event_loop()

asyncio.to_thread()

loop.run_in_executor()

@pytest.mark.asyncio