I am not sure why this behavior is this way. at beginning of script, i want to create a bunch of empty lists and use each one for its own purpose. however, updating one list seems to update the others. >>> a = b = c = [] >>> a.append('1') >>> a.append('1') >>> a.append('1') >>> c ['1', '1', '1'] >>> a ['1', '1', '1'] >>> b ['1', '1', '1']