Asyncio

This is your reference for Python's async/await concurrency model, covering everything from basic coroutines to production patterns with aiohttp and FastAPI. You get practical examples of asyncio.gather() for parallel tasks, proper error handling with return_exceptions, and the often misunderstood event loop mechanics. The blocking I/O section with run_in_executor is especially useful since mixing sync and async code trips up most people. It includes the primitives you actually need like locks and queues, plus real world patterns for async HTTP clients, database connections, and WebSocket handling. The code examples are complete and runnable, not fragments. Honestly, this covers about 90% of what you'll encounter in async Python work, and the progressive disclosure summary is a solid quick reference when you forget the syntax.

skills.sh installs: 494
GitHub stars: 79
last updated: Aug 21, 2026

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$ npx -y skills add bobmatnyc/claude-mpm-skills --skill asyncio --agent claude-code

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Python asyncio - Async/Await Concurrency

Overview

Python's asyncio library enables writing concurrent code using async/await syntax. It's ideal for I/O-bound operations like HTTP requests, database queries, file operations, and WebSocket connections. asyncio provides non-blocking execution without the complexity of threading or multiprocessing.

Key Features:

async/await syntax for readable concurrent code
Event loop for managing concurrent operations
Tasks for running multiple coroutines concurrently
Primitives: locks, semaphores, events, queues
HTTP client/server with aiohttp
Database async support (asyncpg, aiomysql, motor)
FastAPI async endpoints
WebSocket support
Background task management

Installation:

# asyncio is built-in (Python 3.7+)

# Async HTTP client
pip install aiohttp

# Async HTTP requests (alternative)
pip install httpx

# Async database drivers
pip install asyncpg aiomysql motor  # PostgreSQL, MySQL, MongoDB

# FastAPI with async support
pip install fastapi uvicorn[standard]

# Async testing
pip install pytest-asyncio