title: Call external program from python and get its output
body: <p>I want to call a program (<code>.exe</code>), which is written in C++ and compiled, from Python. The executable takes as input two files and returns a score. </p>
  
  <p>I need to do this for multiple files. So, I would like to write a small script in python which loops over multiple files, passes them to the executable and gets back the values. </p>
  
  <p>Now, I have done my search and I know about SWIG and Boost::Python may be an option but I was trying to find if there is an easier way. I do not need to 'extend' the C++ program. I simply want to call it just like I would from a command line and get the returned number. </p>