Calling C++ code from Python

sum

import ctypes
 
_sum = ctypes.CDLL('./sum.so')
_sum.our_function.argtypes = (ctypes.c_int, ctypes.POINTER(ctypes.c_int))
 
def our_function(numbers):
    global _sum
    num_numbers = len(numbers)
    array_type = ctypes.c_int * num_numbers
    result = _sum.our_function(ctypes.c_int(num_numbers), array_type(*numbers))
    return int(result)

print our_function([1,2,-3,4,-5,6])

# g++ -shared -Wl,-install_name,sum.so -o sum.so -fPIC sum.cpp
# important hint, use extern in Cpp file - http://stackoverflow.com/questions/2900512/ctypes-symbol-not-found-for-dynamic-library-in-osx
# http://jjd-comp.che.wisc.edu/index.php/PythonCtypesTutorial
#