Some style nits. Also clarify in the docstrings what __sizeof__ does.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 5405fec..e88ca05 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -3421,7 +3421,7 @@
         {"__format__", object_format, METH_VARARGS,
          PyDoc_STR("default object formatter")},
         {"__sizeof__", object_sizeof, METH_NOARGS,
-         PyDoc_STR("__sizeof__() -> size of object in bytes")},
+         PyDoc_STR("__sizeof__() -> size of object in memory, in bytes")},
 	{0}
 };