Why Are Coroutines Useful?

Coroutines are Python's answer to slow I/O. When a coroutine hits a wait – network, disk, database – the event loop can switch to something else, so the rest of your code keeps running.

Typical I/O you'll await:

• HTTP calls (pyfetch())
• File or database reads/writes
• External devices or browser APIs

from pyodide.http import pyfetch

resp = await pyfetch("/api/boards")
data = await resp.json()

Coroutines help us perform I/O without forcing our entire program to freeze up while we wait for a response.