Arguments and function call

Question

Here is my code:

from telegram.ext import *
updater=Updater(token="")
dis = updater.dispatcher
def echo(update, context):
    context.bot.send_message(chat_id = update.message.chat_id, text = update.message.txt)
dis.add_handler(MessageHandler(Filters.text,echo))
def main():
    updater.start_polling()
    updater.idle()
if __name__=="__main__":
    main()

How is the echo function called and how are the arguments sent to the function. Which arguments are actually sent?

Answer 1

MessageHandler(Filters.text, echo) saves a saves a reference to the echo function in the MessageHandler object, and dis.add_handler() registers this handler in the updater.dispatcher object. The Telegram module calls the function automatically when appropriate, passing the update and context arguments.

This is an example of a callback function .