Thank you Chris :) ..I will check it...
On Sun, Apr 15, 2012 at 3:21 PM, Chris Angelico <ros...@gmail.com> wrote:
> On Sun, Apr 15, 2012 at 7:15 PM, Nibin V M <nibi...@gmail.com> wrote:
> > res_own_file = open('/bah')
> > res_own_list = res_own_file.readline()
> > res_tot_list=[]
> > while res_own_list:
> > res_own_list=res_own_list.strip()
> > res_own_list=res_own_list.replace(' ', '')
> > res_name=res_own_list.split(':')
> > if res_name[1:2] not in res_tot_list:
> > res_tot_list.append(res_name[1:2])
> > res_own_list = res_own_file.readline()
>
> You can iterate over the file thus:
>
> for res_own_list in res_own_file:
> # body of loop here
>
> That saves you the trouble of making sure you do the next readline at
> the bottom, too.
>
> (You may also want to consider using the 'with' statement to guarantee
> a timely closing of the file. Outside the scope of this mail though.)
>
> > As you can see above, I am reading each line, cut a particular field and
> > sort a unique list from it...I have two questions here
> >
> > 1. If I have to check the file again from beginning, I can't do it
> without
> > closing and re-opening file since the file pointer is assigned to the
> EOF of
> > the opened file right? If so, is there any alliterative method to do it?
> I
> > don't wish to mess the script with multiple file open-close code!
>
> You should be able to use res_own_file.seek(0) to do that. I haven't
> tested your code, but that ought to work. If it fails, post code that
> uses seek and the error message you get, and someone will doubtless
> know what's wrong.
>
> > 2. If I print res_name, it will display like ['one', 'two']. If I
> > print res_name[0], it will display one ; but if I print res_name[1] it
> > will display error out of index instead of two. From my code, when I use
> > res_name[1:2] it's displaying second filed. Why it is behaving like this?
>
> My guess here is that at the end of the file, you get a blank line.
> When you use [1:2] syntax, you get back an empty list if the indices
> are out of bounds; but [1] will throw an error.
>
> if res_name[1:2] not in res_tot_list:
> res_tot_list.append(res_name[1:2])
>
> I think this list is just to collect unique entries, yes? If so, a set
> may be more to your liking. Check out:
> http://docs.python.org/py3k/library/stdtypes.html#set
>
> Hope that's of some value!
>
> Chris Angelico
> --
> http://mail.python.org/mailman/listinfo/python-list
>
--
Regards....
Nibin.
http://TechsWare.in
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