Mike Kent wrote: > Roman wrote: > > Thanks for your help > > > > My intention is to create matrix based on parsed csv file. So, I would > > like to have a list of columns (which are also lists). > > > > I have made the following changes and it still doesn't work. > > > > > > cnt = 0 > > p=[[], [], [], [], [], [], [], [], [], [], []] > > reader = csv.reader(file("f:\webserver\inp.txt"), dialect="excel", > > quotechar="'", delimiter='\t') > > for line in reader: > > if cnt > 6: > > break > > j = 0 > > for col in line: > > p[j].append(col) > > j=j+1 > > cnt = cnt + 1 > > > > print p > > p[j] does not give you a reference to an element inside p. It gives > you a new sublist containing one element from p. You then append a > column to that sublist. Then, since you do nothing more with that > sublist, YOU THROW IT AWAY. > > Try doing: > > p[j] = p[j].append(col) >
No, this doesn't work. append is an in-place operation, and you'll end up setting p[j] to it's return, which is None. Iain -- http://mail.python.org/mailman/listinfo/python-list