Ian Bicking wrote: ... > But to me I expect "obj.append(x)" to imply "obj[-1] == x" and also that It does imply that when obj is a Python list, yes. > "obj.append(x)" is equivalent to "obj += x". But not that -- *never*. "obj += x" is rather akin to obj.extend(x), and that, of course, is very different from obj.append(x). Alex