python: expose Py_SetProgramName and Py_GetProgramName

Fixes #71.

init.go

@@ -0,0 +1,43 @@
+package python
+
+// #include "go-python.h"
+// char *gopy_ProgName = NULL;
+import "C"
+
+import (
+	"unsafe"
+)
+
+// Py_SetProgramName should be called before Py_Initialize() is called for
+// the first time, if it is called at all.
+// It tells the interpreter the value of the argv[0] argument to the main()
+// function of the program. This is used by Py_GetPath() and some other
+// functions below to find the Python run-time libraries relative to the
+// interpreter executable. The default value is 'python'. The argument should
+// point to a zero-terminated character string in static storage whose contents
+// will not change for the duration of the program’s execution.
+// No code in the Python interpreter will change the contents of this storage.
+func Py_SetProgramName(name string) {
+	C.gopy_ProgName = C.CString(name)
+	C.Py_SetProgramName(C.gopy_ProgName)
+}
+
+// Py_GetProgramName returns the program name set with Py_SetProgramName(),
+// or the default.
+// The returned string points into static storage; the caller should not
+// modify its value.
+func Py_GetProgramName() string {
+	cname := C.Py_GetProgramName()
+	return C.GoString(cname)
+}
+
+// PySys_SetArgv initializes the 'sys.argv' array in python.
+func PySys_SetArgv(argv []string) {
+	argc := C.int(len(argv))
+	cargs := make([]*C.char, len(argv))
+	for idx, arg := range argv {
+		cargs[idx] = C.CString(arg)
+		defer C.free(unsafe.Pointer(cargs[idx]))
+	}
+	C.PySys_SetArgv(argc, &cargs[0])
+}

init_test.go

@@ -0,0 +1,20 @@
+package python_test
+
+import (
+	"testing"
+
+	python "github.com/sbinet/go-python"
+)
+
+func TestProgramName(t *testing.T) {
+	const want = "foo.exe"
+	python.Py_SetProgramName(want)
+	err := python.Initialize()
+	if err != nil {
+		t.Fatal(err)
+	}
+	name := python.Py_GetProgramName()
+	if name != want {
+		t.Fatalf("got=%q. want=%q", name, want)
+	}
+}

utilities.go

@@ -468,16 +468,3 @@ func PyEval_GetFuncDesc(fct *PyObject) string {
 	c_name := C.PyEval_GetFuncDesc(topy(fct))
 	return C.GoString(c_name)
 }
-
-// PySys_SetArgv initializes the 'sys.argv' array in python.
-func PySys_SetArgv(argv []string) {
-	argc := C.int(len(argv))
-	cargs := make([]*C.char, len(argv))
-	for idx, arg := range argv {
-		cargs[idx] = C.CString(arg)
-		defer C.free(unsafe.Pointer(cargs[idx]))
-	}
-	C.PySys_SetArgv(argc, &cargs[0])
-}
-
-// EOF