Address Serhiy's review

* Add more tests
* Add 'const'

Lib/test/test_capi/test_import.py

@@ -322,6 +322,21 @@ def check_getmoduleattr(self, getmoduleattr):
         self.assertIs(getmoduleattr('sys', 'argv'), sys.argv)
         self.assertIs(getmoduleattr('types', 'ModuleType'), types.ModuleType)
 
+        # module name containing a dot
+        attr = getmoduleattr('email.message', 'Message')
+        from email.message import Message
+        self.assertIs(attr, Message)
+
+        with self.assertRaises(ImportError):
+            # nonexistent module
+            getmoduleattr('nonexistentmodule', 'attr')
+        with self.assertRaises(AttributeError):
+            # nonexistent attribute
+            getmoduleattr('sys', 'nonexistentattr')
+        with self.assertRaises(AttributeError):
+            # attribute name containing a dot
+            getmoduleattr('sys', 'implementation.name')
+
     def test_getmoduleattr(self):
         # Test PyImport_GetModuleAttr()
         getmoduleattr = _testcapi.PyImport_GetModuleAttr

Modules/_testcapi/import.c

@@ -20,7 +20,7 @@ pyimport_getmoduleattr(PyObject *self, PyObject *args)
 static PyObject *
 pyimport_getmoduleattrstring(PyObject *self, PyObject *args)
 {
-    char *mod_name, *attr_name;
+    const char *mod_name, *attr_name;
     Py_ssize_t len;
     if (!PyArg_ParseTuple(args, "z#z#", &mod_name, &len, &attr_name, &len)) {
         return NULL;