Correct co_names documentation in inspect module

Lib/inspect.py

@@ -277,7 +277,7 @@ def iscode(object):
         co_kwonlyargcount   number of keyword only arguments (not including ** arg)
         co_lnotab           encoded mapping of line numbers to bytecode indices
         co_name             name with which this code object was defined
-        co_names            tuple of names of local variables
+        co_names            tuple of names other than arguments and function locals
         co_nlocals          number of local variables
         co_stacksize        virtual machine stack space required
         co_varnames         tuple of names of arguments and local variables"""