Async Programming

Purpose

Async/await enables non-blocking concurrent operations. This skill documents patterns for safe async code.

When to Use

Use this skill when:

• Working with I/O operations
• Building concurrent systems
• Managing timeouts
• Implementing cancellation

Key Patterns

1. All I/O is Async

Never use blocking I/O:

# WRONG
with open(file) as f:
    data = json.load(f)

# CORRECT
async with aiofiles.open(file) as f:
    data = await f.read()

2. Timeout Protection

All async operations need timeouts:

try:
    result = await asyncio.wait_for(operation(), timeout=30.0)
except asyncio.TimeoutError:
    # Handle timeout

3. Error Handling

Async operations need proper error handling:

async def safe_operation():
    try:
        return await risky_operation()
    except Exception as e:
        logger.error(f"Operation failed: {e}")
        raise TradingError(...) from e

See Also

• Python asyncio: https://docs.python.org/3/library/asyncio.html