Telepot is a python based telegram bot framework which is lightweight, easy to use and supports all of the up-to-date telegram features. For example, I was able to write a small telegram bot running on Pi2 which takes and sends a photo with only few lines using it. Here is how.
1) Although Telepot supports python 2.7 without async feature, I wanted to use Python 3.x. However, the latest Telepot supports async requires Python 3.5 so I had to download and build Python 3.5 on my Pi2. I followed the instruction introduced here https://sowingseasons.com/blog/software/2016/01/building-python-3-4-on-raspberry-pi-2/19864079 except using python source https://www.python.org/ftp/python/3.5.2/Python-3.5.2.tgz
2) Telepot also provides basic samples. You can also find out other API usages through test code. ‘couter/countera’ example is simple but a good start points if you only require receiving telegram message and sending a reply back.
3) Of course you’ll need a Telegram Bot account. There’s a bot named ‘@BotFather’ which does making a bot for you and makes you setting basic info of it. Just initiate a talk to the account and detailed instruction described here: https://core.telegram.org/bots
4) I used the https://github.com/nickoala/telepot/blob/master/examples/chat/countera.py as the starting point. From the source, MessageCounter.on_chat_message will be called responds to the user’s message. If you want to make the CCTV like telegram bot, then just take a picture and send it back within the method.
5) Takes a picture using the picamera module and replies with it. Remove the temporary saved picture after sending it.
6) here is the result: https://gist.github.com/heejune/afd77aeec49e836fa549fc025962ddd8