Il Sat, 07 Mar 2009 00:05:53 -0200, Gabriel Genellina ha scritto: > En Fri, 06 Mar 2009 21:31:01 -0200, mattia <ger...@gmail.com> escribió: > >> Thanks, I've found another solution here: >> http://www.obitko.com/tutorials/ >> genetic-algorithms/selection.php >> so here is my implementation: >> >> >> def get_fap(fitness, population): >> fap = [] >> total = 0 >> for x in population: >> f = fitness(x) >> fap += [(f, x)] >> total += f >> return sorted(fap, reverse=True), total > > Imagine you're working with someone side by side. You write a note in a > piece of paper, put it into an envelope, and hand it to your co-worker. > He opens the envelope, throws it away, takes the note and files it > inside a folder right at the end. And you do this over and over. What's > wrong in this story? > > Please save our trees! Don't waste so many envelopes - that's just what > this line does: > > fap += [(f, x)] > > Environmentally friendly Pythoneers avoid using discardable intermediate > envelopes: > > fap.append((f, x)) > > Please recycle!
Yes, sorry, I have to recycle! But how about this: >>> rw = [[2,4], [4,5,6],[5,5]] >>> rw += [[1,1]]*2 >>> rw [[2, 4], [4, 5, 6], [5, 5], [1, 1], [1, 1]] >>> rw = [[2,4], [4,5,6],[5,5]] >>> rw.append([1,1]*2) >>> rw [[2, 4], [4, 5, 6], [5, 5], [1, 1, 1, 1]] >>> rw = [[2,4], [4,5,6],[5,5]] >>> rw.append([[1,1]]*2) >>> rw [[2, 4], [4, 5, 6], [5, 5], [[1, 1], [1, 1]]] >>> How can I recicle in this way using append? -- http://mail.python.org/mailman/listinfo/python-list
