Based on https://github.com/python-telegram-bot/python-telegram-bot/blob/master/examples/echobot2.py
$ sudo pip install python-telegram-bot
Just create functions to define what you want to do with the bot, and link it to commands or messages.
There are just three example functions: one for the /start command, other for the /help command and the last one that echoes all incoming messages.
The bot token goes on the config file (see sample attached).
You can also specify on the config file a list of chat ids so the bot only speaks to whoever you decide.