Python's ``input()`` is blocking, which means the event loop we set
    above can't be running while we're blocking there. This method will
    let the loop run while we wait for input.

async def async_input(prompt):
    """
    Python's ``input()`` is blocking, which means the event loop we set
    above can't be running while we're blocking there. This method will
    let the loop run while we wait for input.
    """
    print(prompt, end='', flush=True)
    return (await loop.run_in_executor(None, sys.stdin.readline)).rstrip()