andrey@valkyrie ~ $ cat p.py import time chars = map(chr, range(0, 255)) q = [] t = time.time() for i in range(0, 1000000): q.append(chr(100)) print "%.3f" % (time.time() - t) q = [] t = time.time() for i in range(0, 1000000): q.append(chars[100]) print "%.3f" % (time.time() - t) andrey@valkyrie ~ $ python p.py 0.806 0.458 andrey@valkyrie ~ $