How to get Python code to work with C++ App?

Question

I have the following python 3 file:

import base64
import xxx

str = xxx.GetString()
str2 = base64.b64encode(str.encode())
str3 = str2.decode()
print str3

xxx is a module exported by some C++ code. This script does not work because calling Py_InitModule on this script returns NULL. The weird thing is if I create a stub xxx.py in the same directory

def GetString() :
    return "test"

and run the original script under python.exe, it works and outputs the base64 string. My question is why doesn't it like the return value of xxx.GetString? In the C++ code, it returns a string object. I hope I have explained my question well enough... this is a strange error.

Answer 1

Er... You have to investigate why Py_InitModule returns NULL. Posting the Python code using that module won't help.

Answer 2

Py_InitModule() is for initializing extension modules written in C, which is not what you are looking for here. If you want to import a module from C, there is a wealth of functions available in the C API: http://docs.python.org/c-api/import.html

But if your aim is really to run a script rather than import a module, you could also use one of the PyRun_XXX() functions described here: http://docs.python.org/c-api/veryhigh.html

Answer 3

I know everybody says this...but: Boost has an awesome library for exposing classes to python and getting data to and fro. If you're having problems, and looking for alternatives is an option I'd highly recommend the boost python library of the C interface. I've used them both, boost wins hands down imo.