code_to_find_chat_id_and_test_bot.py

import telegram

bot = telegram.Bot(token = "INSERT BOT TOKEN HERE")

updates = []
while not updates:
     updates = bot.getUpdates()

print (updates[-1].message.text)
chat_id = updates[-1].message.chat_id

bot.sendMessage(chat_id = chat_id, text = chat_id)