Re-posting in more simple and precise terms from a previous thread http://groups.google.it/group/comp.lang.python/browse_thread/thread/6dd7bd9a09b8a011/5119cf15ebfa38b8
Problem: SWIG doesn't properly wrap c++ arrays of pointers, therefore when you try to call a c++ function which requires them, a TypeError exception is raised. Similar story here: http://osdir.com/ml/programming.swig/2003-02/msg00064.html Already tried: - some ctypes functions - tuple or string instead of list Possibile solutions: something like http://embedded.eecs.berkeley.edu/Alumni/pinhong/scriptEDA/pyTypemapFAQ.html#20 that didn't work either, but I think I was not able to adapt the code to my case, since the example is poorly explained. Code to reproduce error: I made a dptest.cpp function that calculates the sum of an array of pointers to ints. #include "dptest.h" //the header file is just //int sum(int**, int); int sum(int** dp, int len){ int sum = 0; for (int i = 0; i < len; i++){ sum += *(dp[i]); } return sum; } swig -c++ -python, then setup.py build_ext --inplace gets it nicely compiled and wrapped for python use. It also is imported without problems, but then... mat...@matteo:~/lab/sandbox$ python Python 2.5.2 (r252:60911, Oct 5 2008, 19:24:49) [GCC 4.3.2] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import dptest as dp >>> l = [1, 2, 3, 4] >>> size = len(l) >>> dp.sum(l,size) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: in method 'sum', argument 1 of type 'int **' NOTE: A pure c++ program works as expected: #include <iostream> int sum(int**, int); int main(){ int **array_of_ptr = new int*[4]; for (int i = 0; i < 4; i++){ array_of_ptr[i] = new int; *array_of_ptr[i] = i+1; //fill it with 1,2,3,4: 1+2+3+4 = 10 } std::cout << sum(array_of_ptr, 4) << std::endl; } int sum(int** dp, int len){ int sum = 0; for (int i = 0; i < len; i++){ sum += *(dp[i]); } return sum; } compiling and running prints the correct result: mat...@matteo:~/lab/sandbox$ ./purecpp 10 -- http://mail.python.org/mailman/listinfo/python-list
