On Sat, 2006-09-23 at 09:03 -0700, kumar s wrote: > hi, > > thank you. this is not a homework question. > > I have a very huge file of fasta sequence. > > > GeneName xxxxxxxx \t yyyyyyyy > AATTAAGGAAAAAA.......... > > > > > > (1000 lines) > AATAAGGA > >GeneName xxxxxxxx \t yyyyyyyy > GGAGAGAGATTAAGAA > (15000 lines) > > > > when I read this as: > > f2= open('myfile','r') > dat = f2.read().split('\n') > > turned out to be very expensive deal on computer. > > > Instead I tried this: > > dat = f2.read() > > (reading into jumbo file of 19,100,442,1342 lines is > easy but getting into what i want is a problem). > > > I want to create a dictionary where 'GeneName' as key > and sequence of ATGC characters as value > > > biglist = dat.split('\t') > ['GeneName xxxxxxxx','yyyyyyyy','ATTAAGGCCAA'.......] > > Now I want to select ''GeneName xxxxxxxx' into listA > and 'ATTAAGGCCAA' into listB > > so I want to select 0,3,6,9 elements into listA > and 2,5,8,11 and so on elements into listB > > then I can do dict(zip(listA,listB)) > > > > however, the very loops concept is getting blanked out > in my brain when I want to do this: > > for j in range(len(biglist)): > from here .. I cannot think anything..
slices may be the best way to go listA = biglist[0::3] # start from index 0 taking every third element listB = biglist[2::3] # start from index 2 taking every third element > > may be it is just mental block.. thats the reason I > seek help on forum. > > > Thanks > > > > > > --- jim stockford <[EMAIL PROTECTED]> wrote: > > > > > keep a counter in your loop. is this a homework > > question? > > > > On Sep 23, 2006, at 8:34 AM, kumar s wrote: > > > > > hi, > > > > > > the reason could be that I did not quite > > understand > > > the concept of looping > > > > > > I have a list of 48 elements > > > > > > I want to create another two lists , listA and > > listB > > > > > > I want to loop through the list with 48 elements > > and > > > > > > select element with index 0,3,6,9,12 ..etc into > > listA > > > > > > select elements with index 2,5,8,11 etc into > > listB. > > > > > > > > > Could any one help me how can I do that > > > > > > thankyou > > > > > > __________________________________________________ > > > Do You Yahoo!? > > > Tired of spam? Yahoo! Mail has the best spam > > protection around > > > http://mail.yahoo.com > > > _______________________________________________ > > > Tutor maillist - Tutor@python.org > > > http://mail.python.org/mailman/listinfo/tutor > > > > > > > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > _______________________________________________ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor -- Lloyd Kvam Venix Corp _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor