John Salerno wrote: > If I want to create a list of the form [100, 99, 99, 98, 98, 97, 97...] > (where each item is repeated twice after the first one), how might I do > that most efficiently? > > Right now I have this: > > series = [100] > for x in range(10): # just for testing > series.append(series[-1] - 1) > > But of course that only does it once, and I don't want to have to copy > and paste the append line. Perhaps there's a better way than this. > > Thanks.
I know this doesn't beat Edward Elliot's answer, but: py> import operator py> [100] + reduce(operator.add, [[i,i] for i in xrange(99,90,-1)]) [100, 99, 99, 98, 98, 97, 97, 96, 96, 95, 95, 94, 94, 93, 93, 92, 92, 91, 91] -- James Stroud UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
