aiotimeout

Timeout context manager for asyncio Python

Usage

from aiotimeout import timeout

# Will raise an asyncio.TimeoutError
with timeout(1):
    await asyncio.sleep(1.5)

# Will not raise anything
with timeout(1):
    await asyncio.sleep(0.5)

You can respond to a timeout from outside the context by catching asyncio.TimeoutError

try:
    with timeout(1):
        await asyncio.sleep(1.5)
        print('This line is not reached')
except asyncio.TimeoutError:
    print('Timed out')

or you can respond to a timeout from inside the context by catching asyncio.CancelledError and re-raising.

try:
    with timeout(1):
        try:
            await asyncio.sleep(1.5)
        except asyncio.CancelledError
            print('Doing some cleanup')
            raise
except asyncio.TimeoutError:
    print('Timed out')

Differences to alternatives

• asyncio.wait_for does not offer a context manager. In some cases a context manager is clearer.

• asyncio.wait_for creates/uses an extra task. In some cases this is not necessary, and an extra task adds non-determinism in terms of sequence of operations.

• Clearer internal code [in the author's opinion]. Rather than a custom class, contextlib.contextmanager is used.