Python C-API access String constants -

i wanted implement library have written python in c using c-api of python. in python can declare "constants" in module stating:

red = "red"   # not constant, know blue = "blue" # suitable, nevertheless  def solve(img_h):     # awesome computations     return (red, blue)[some_flag] 

those constants later returned functions offered module. have trouble doing same thing in c. here got far:

pymodinit_func pyinit_puzzler(void) {     pyobject* module = pymodule_create(&module);     (void) pymodule_addstringconstant(module, "blue",   "blue");     (void) pymodule_addstringconstant(module, "red",    "red");     return module; }  pyobject* solve(pyobject* module, pyobject* file_handle) {     // awesome computations based on file     // involves huge amounts of memory management, efficient in c     // problem: how return stringconstants here?     return some_flag ? blue : red; } 

i have marked problematic part. after add string constants module pymodule_addstringconstant(module, "foo", "foo"); how can return them pyobject* methods? need increase ref-counter when return them?

since pymodule_addstringconstant(module, name, value) adds constant module, should available module's dictionary can acquired pymodule_getdict(module). can access attribute module via dictionary using pydict_getitemstring(dict, key) how can access constants module (after definitions):

// module dict. borrowed reference. pyobject* module_dict = pymodule_getdict(module);  // blue constant. borrowed reference. pyobject* blue = pydict_getitemstring(module_dict, "blue");  // red constant. borrowed reference. pyobject* red = pydict_getitemstring(module_dict, "red"); 

to put context solve() function, want similar to:

pyobject* solve(pyobject* module, pyobject* file_handle) {     // awesome computations based on file     // involves huge amounts of memory management, efficient in c      // return string constant @ end.     pyobject* module_dict = pymodule_getdict(module);     pyobject* constant = null;     if (some_flag) {         // return blue constant. since blue borrowed          // reference, increment reference count before          // returning it.         constant = pydict_getitemstring(module_dict, "blue");         py_incref(constant);     } else {         // return red constant. since red borrowed          // reference, increment reference count before          // returning it.         constant = pydict_getitemstring(module_dict, "red");         py_incref(constant);     }      // note: before return, make sure release owned     // references function acquired. `module_dict`     // not need released because merely "borrowed".      // return constant (either blue or red) owned     // reference. whatever calls `solve()` must make sure     // release returned reference `py_decref()`.     return constant; }