Add more examples.

Author: serhiy-storchaka

Modules/_interpretersmodule.c

@@ -1245,14 +1245,11 @@ interp_get_config(PyObject *self, PyObject *args, PyObject *kwds)
     PyObject *idobj = NULL;
     int restricted = 0;
     if (!PyArg_ParseTupleAndKeywords(args, kwds,
-                                     "O|$p:get_config", kwlist,
+                                     "O?|$p:get_config", kwlist,
                                      &idobj, &restricted))
     {
         return NULL;
     }
-    if (idobj == Py_None) {
-        idobj = NULL;
-    }
 
     int reqready = 0;
     PyInterpreterState *interp = \
@@ -1369,14 +1366,14 @@ capture_exception(PyObject *self, PyObject *args, PyObject *kwds)
     static char *kwlist[] = {"exc", NULL};
     PyObject *exc_arg = NULL;
     if (!PyArg_ParseTupleAndKeywords(args, kwds,
-                                     "|O:capture_exception", kwlist,
+                                     "|O?:capture_exception", kwlist,
                                      &exc_arg))
     {
         return NULL;
     }
 
     PyObject *exc = exc_arg;
-    if (exc == NULL || exc == Py_None) {
+    if (exc == NULL) {
         exc = PyErr_GetRaisedException();
         if (exc == NULL) {
             Py_RETURN_NONE;

Modules/_threadmodule.c

@@ -641,12 +641,12 @@ PyThreadHandleObject_join(PyObject *op, PyObject *args)
     PyThreadHandleObject *self = (PyThreadHandleObject*)op;
 
     PyObject *timeout_obj = NULL;
-    if (!PyArg_ParseTuple(args, "|O:join", &timeout_obj)) {
+    if (!PyArg_ParseTuple(args, "|O?:join", &timeout_obj)) {
         return NULL;
     }
 
     PyTime_t timeout_ns = -1;
-    if (timeout_obj != NULL && timeout_obj != Py_None) {
+    if (timeout_obj != NULL) {
         if (_PyTime_FromSecondsObject(&timeout_ns, timeout_obj,
                                       _PyTime_ROUND_TIMEOUT) < 0) {
             return NULL;

Modules/mmapmodule.c

@@ -1689,7 +1689,7 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict)
     DWORD off_lo;       /* lower 32 bits of offset */
     DWORD size_hi;      /* upper 32 bits of size */
     DWORD size_lo;      /* lower 32 bits of size */
-    PyObject *tagname = Py_None;
+    PyObject *tagname = NULL;
     DWORD dwErr = 0;
     int fileno;
     HANDLE fh = 0;
@@ -1699,7 +1699,7 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict)
                                 "tagname",
                                 "access", "offset", NULL };
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "in|OiL", keywords,
+    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "in|U?iL", keywords,
                                      &fileno, &map_size,
                                      &tagname, &access, &offset)) {
         return NULL;
@@ -1832,13 +1832,7 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict)
     m_obj->weakreflist = NULL;
     m_obj->exports = 0;
     /* set the tag name */
-    if (!Py_IsNone(tagname)) {
-        if (!PyUnicode_Check(tagname)) {
-            Py_DECREF(m_obj);
-            return PyErr_Format(PyExc_TypeError, "expected str or None for "
-                                "'tagname', not %.200s",
-                                Py_TYPE(tagname)->tp_name);
-        }
+    if (tagname != NULL) {
         m_obj->tagname = PyUnicode_AsWideCharString(tagname, NULL);
         if (m_obj->tagname == NULL) {
             Py_DECREF(m_obj);