from line.messaging import Channel
from line.messaging.events import MessageEvent
from line.messaging.message import TextMessage

webhook = Channel(
    channel_secret='your channel secret',
    channel_access_token='your channel access token'
).get_webhook()

@webhook.event_handler
def test_handler(event):
    if isinstance(event, MessageEvent) and isinstance(event.message, TextMessage):
        event.reply(event.message)
        event.source.send_message(TextMessage(message='test'))

webhook.run(certfile='./test.cert', keyfile='./test.key')