Demo app shows std::stable_partition and std::rotate works

From the beginning of Sean Parent’s great C++ talk, he represented two std algorithms people may not be familiar of. It’s ‘std::stable_partition’ and ‘std::rotate’.

I made a small demo application shows how the two algorithms works. It’s Qt5 based application so that you can freely compile and run from Windows, mac or Linux. Grab the code here:

std::stable_partition example

std::rotate example



Running a CCTV Telegram Bot on your Pi


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 except using python source

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:

4) I used the 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: