On Wed, Sep 7, 2011 at 2:25 PM, Hugo Arts <hugo.yo...@gmail.com> wrote: > forgot to forward this to list, sorry. > > > ---------- Forwarded message ---------- > From: Hugo Arts <hugo.yo...@gmail.com> > Date: Wed, Sep 7, 2011 at 8:24 AM > Subject: Re: [Tutor] how to sort the file out > To: lina <lina.lastn...@gmail.com> > > > On Wed, Sep 7, 2011 at 8:16 AM, lina <lina.lastn...@gmail.com> wrote: >> On Wed, Sep 7, 2011 at 1:28 PM, Hugo Arts <hugo.yo...@gmail.com> wrote: >>> I was assuming that the numbers were field 1, and the letter/number >>> combinations were field 2. If I understand him correctly, he wants the >> >> Yes. >> >>> lines in file 2 to be arranged such that the order of field two is the >>> same as it is in file 1. In that case, you can do it with one sexy >>> sort() call (and a little preprocessing to load the files), but I >>> don't want to get all into explain and then realize he wants something >>> totally different. >> You understand right. >> > > Well, it is fairly simple. You grab field2 from file1, and put all the > items into a list (should be easy right? open(), readlines(), split(), > grab second item). Then, you grab file2 as a list of tuples (same > procedure as the first file, but you just put the results of split() > right into the list. Then you sort with a key like so: > > list2.sort(key=lambda x: list1.index(x[1])) > > You see? For each item in the second list, we grab field 2, and look > up what index it has in list1. Then we use that index as the sort key. > That way they'll be sorted like file1 is.
not easy to me. Sign ... I may do it by hand, cut and pasta following the orders. > > After that it's just a matter of writing back to the file, easy peasy. > > HTH, > Hugo > _______________________________________________ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor > -- Best Regards, lina _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
