Avoid inefficient way to call functions without argument

Don't pass "()" format to PyObject_CallXXX() to call a function without
argument: pass NULL as the format string instead. It avoids to have to parse a
string to produce 0 argument.

1 files changed, 1 insertions, 1 deletions

diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 3410dfe..1675102 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -2009,7 +2009,7 @@ defdict_reduce(defdictobject *dd)
         args = PyTuple_Pack(1, dd->default_factory);
     if (args == NULL)
         return NULL;
-    items = _PyObject_CallMethodId((PyObject *)dd, &PyId_items, "()");
+    items = _PyObject_CallMethodId((PyObject *)dd, &PyId_items, NULL);
     if (items == NULL) {
         Py_DECREF(args);
         return NULL;