Await in loop (ARCH2030)

Key python.async.await-in-loop · Severity info · Category async

Awaiting each element inside a loop body serializes independent async operations. With asyncio.gather they can run concurrently, cutting total latency.

Incorrect

async def load_all(ids):
    results = []
    for i in ids:
        results.append(await fetch(i))  # serial
    return results

Correct

import asyncio

async def load_all(ids):
    return await asyncio.gather(*(fetch(i) for i in ids))  # concurrent

Fix

Collect independent calls with asyncio.gather and await them concurrently in one pass.