Creating Coroutines

While the await keyword is used to wait for a coroutine to complete, the async keyword is used to create a coroutine function. When we call an async function, it returns a coroutine object that can later be awaited.

async def get_issue_data(issue_id: str) -> dict[str, str]:
    resp = await pyfetch(f"/api/issues/{issue_id}")
    return await resp.json()


coroutine = get_issue_data("ISS‑42")  # returns immediately – nothing has executed yet
result = await coroutine  # now the coroutine runs and yields the data

1. async def always returns a coroutine object, even if there's no await inside.

2. The await keyword can only be used inside an async function or at top level in Pyodide.

3. A coroutine doesn't run until you await it or schedule it, e.g. with asyncio.run()