readline() - problem

[Paul Hankin]

On Oct 2, 12:25 pm, pi... at kolodziejczyk.waw.pl wrote:
> Hi!
> I'm a new user of python, and have problem.
> I have a plain ascii file:
> 1aaaaaaaaaaaa1......1
> 1cccccccccccc2......1
> 1xxxxxxxxxxxx1......1
> I want to create a new file which contains only lines with '1' on 15th
> position.
> I've tried this:
>
> import string
> f=open('/test/test.asc','r')
> o=open('/test/out.asc','w')
> for line in f:
>     s= f.readline()
>     if s[15]=='1' :
>        o.write(s)
> o.close()
> f.close()
>
> Why it doesn't work ('s' contains ' ' )?

You're iterating over the lines in f already, so no need to call
readline.

for line in f:
  if line[15] == '1':
    o.write(line)

--
Paul Hankin