Tim Peters kirjoitti: > [Simon Schuster] >> following this tutorial, > > Which tutorial?
He's reading this tutorial which he was already advised not to do: =========================================== =========================================== =========================================== Simon Schuster wrote: > > I'm new to python, and almost new to programming in general. I'm at > > http://www.pasteur.fr/formation/infobio/python/ch04.html in that > > tutorial, and my 'count' function (if it's called a function?) isn't > > working suddenly. > > >>>> > >>> x = "fljshfjh" >>>> > >>> x > > 'fljshfjh' >>>> > >>> count(x, 'h') > > Traceback (most recent call last): > > File "<stdin>", line 1, in ? > > NameError: name 'count' is not defined > > > > I'm not sure what changed, because it used to work. anyhow thanks a lot! > > Probably because you omiitted the line from string import * However IMHO your use of a tutorial which: (1) introduces "from some_module import *" as though it is the normal way of doing things From chapter 1: """ Some magical stuff, that will be explained later: >>> from string import * """ That's *bad* magic (2) is still using (outdated) functions in the string module instead of teaching string methods should be discontinued immediately. You may wish to have a look at some of the /other/ tutorials mentioned on this page: http://wiki.python.org/moin/BeginnersGuide/NonProgrammers HTH, John =========================================== =========================================== =========================================== > >> I copied and pasted: >> >> from string import * >> >> cds = """atgagtgaacgtctgagcattaccccgctggggccgtatatcggcgcacaaa >> tttcgggtgccgacctgacgcgcccgttaagcgataatcagtttgaacagctttaccatgcggtg >> ctgcgccatcaggtggtgtttctacgcgatcaagctattacgccgcagcagcaacgcgcgctggc >> ccagcgttttggcgaattgcatattcaccctgtttacccgcatgccgaaggggttgacgagatca >> tcgtgctggatacccataacgataatccgccagataacgacaactggcataccgatgtgacattt >> attgaaacgccacccgcaggggcgattctggcagctaaagagttaccttcgaccggcggtgatac >> gctctggaccagcggtattgcggcctatgaggcgctctctgttcccttccgccagctgctgagtg >> ggctgcgtgcggagcatgatttccgtaaatcgttcccggaatacaaataccgcaaaaccgaggag >> gaacatcaacgctggcgcgaggcggtcgcgaaaaacccgccgttgctacatccggtggtgcgaac >> gcatccggtgagcggtaaacaggcgctgtttgtgaatgaaggctttactacgcgaattgttgatg >> tgagcgagaaagagagcgaagccttgttaagttttttgtttgcccatatcaccaaaccggagttt >> caggtgcgctggcgctggcaaccaaatgatattgcgatttgggataaccgcgtgacccagcacta >> tgccaatgccgattacctgccacagcgacggataatgcatcgggcgacgatccttggggataaac >> cgttttatcgggcggggtaa""".replace("\n","") >> >> gc = float(count(cds, 'g') + count(cds, 'c'))/ len(cds) >> >> print gc >> >> -fin- >> >> which should yield: 0.54460093896713613.. >> >> but when I ran it I got: 0.544600938967 >> >> looking now I see it's truncating after a certain number of decimal >> places. any ideas why? > > Read the Python Tutorial appendix on floating-point issues: > > http://docs.python.org/tut/node16.html > > As it says, str(a_float) rounds to 12 significant digits, and > repr(a_float) to 17. The `print` statement implicitly applies str() > to each item it prints. Cheers, Jussi Salmela -- http://mail.python.org/mailman/listinfo/python-list
