There are a lot of questions and answers on how to parse/create config files in python and C++ individually. In my case, I have one single config file and need to be processed (read/write) by both python and C++. 
In python world, ConfigParser is popular; while in C++, libconfig looks nice. But they are using different formats. What I am looking for is a stone being able to kill two birds at the same time. :)
An obvious solution that comes to mind is to go with something along the lines of YAML or JSON which you should find support for across many languages.
Config File Process in Python and C++