Ctypes Strings

I've written bulk of PySWIP last summer, it is based on Nathan Denny's proolog.py. This is the first project that I used ctypes, a fantastic package which allows calling C functions from dynamic libraries that I use to link libpl.so (Linux) or libpl.dll (Windows) of SWI-Prolog. One of the difficulties I had back then was finding the corresponding ctypes code for PL_get_chars which is defined at SWI-Prolog.h as follows:

PL_EXPORT(int) PL_get_chars(term_t t,
    char **s, unsigned int flags);

I use that function in queryGenerator:

answer = (c_char_p*maxsubresult)()
while PL_get_list(swipl_list, swipl_head, swipl_list):
    PL_get_chars(swipl_head, answer,

And, cstr2pystr is a home-madePython function to convert from a C-string to a Python string in an awful way ;)

That was until I've seen this article in the blog of a good person called Erik Strandberg. His article is about using ctypes, and especially using ctypes types which inspired me to write the code below (knowing that a function called addressof existed helped much!), thanks Erik :)

answer = c_char_p("\x00"*MAXSTR)
while PL_get_list(swipl_list, swipl_head, swipl_list):
    PL_get_chars(swipl_head, addressof(answer),