as the += notation seems to be a syntaxic sugar layer that has to be converted to i = i + 1 anyway.
That has always been my understanding. The faster way is to append to a list as concatenating usually, requires the original string, accessing an intermediate block of memory, and the memory for the final string. x_list.append(value) to_string = "".join(x_list) -- http://mail.python.org/mailman/listinfo/python-list