How can I add a connection timeout with asyncio?
You can wrap the call to open_connection in asyncio.wait_for, which allows you to specify a timeout:
with suppress(ssl.CertificateError): fut = asyncio.open_connection(host[1], 443, ssl=True) try: # Wait for 3 seconds, then raise TimeoutError reader, writer = yield from asyncio.wait_for(fut, timeout=3) except asyncio.TimeoutError: print("Timeout, skipping {}".format(host[1])) continueNote that when TimeoutError is raised, the open_connection coroutine is also cancelled. If you don't want it to be cancelled (though I think you do want it to be cancelled in this case), you have wrap the call in asyncio.shield.