how to pass a value to c++ from python and back?

Question

i would like to pass values from python to a c++ program for an encryption from inside a python program and then return the value from there to the python program . how to do it?

Answer 1

If you want to use some existing Unix-style command line utility that reads from stdin and writes to stdout, you can use subprocess.Popen by using Popen.communicate():

import subprocess

p = subprocess.Popen(["/your/app"], stdin=subprocess.PIPE, stdout=subprocess.PIPE)
output = p.communicate(input)[0]

Answer 2

As said msw in the other post, the proper solution is using PyObject. If you want to have a two-way communication between C++ & Python, Boost Python would be interesting for you. Take a look at website Boost Python,

This post would also be interesting: How to expose a C++ class to Python without building a module