l[0] += [1] is the same as
l[0] = l[0] + [1] Does that make the reason for the error clearer? The problem is the attempt to assign a value to l[0]. It is not the same as e = l[0] e += [1] which is the equivalent to e = l[0] e = e + [1] This never assigns a value to l[0]. Schiavo Simon _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
