On Mon, Jan 28, 2013 at 6:05 PM, Dennis Lee Bieber <wlfr...@ix.netcom.com>wrote:
> On Mon, 28 Jan 2013 14:31:31 +0100, inshu chauhan
> <insidesh...@gmail.com> declaimed the following in
> gmane.comp.python.general:
>
> > In the code below I am trying to read 2 files f1 and f2 , extract some
> data
> > from them and then trying to write them into a single file that is 'nf'.
> >
> > import cv
> > f1 = open(r"Z:\modules\Feature_Vectors_300.arff")
> > f2 = open(r"Z:\modules\Feature_Vectors_300_Pclass.arff")
> > nf = open(r"Z:\modules\trial.arff", "w")
> >
> >
> > for l in f1:
> > sp = l.split(",")
>
> If you are going to be splitting on commas, you might want to read
> up on the csv (comma separate values) module
>
The csv module has many fuctions but not of much use to me and it makes my
programme slower
>
> >
> > if len(sp)!= 12:
> > continue
> > else:
>
> Given the apparent block structure, you could drop the
> continue/else, and more cleanly just use
>
Yeah, Thats Right
>
> if len(sp) == 12:
> > ix = sp[0].strip()
> > iy = sp[1].strip()
> > print ix, iy
> >
> > for s in f2:
>
> It's been mentioned that the indentation is wrong here
>
I dont know why the indentation is wrong ?
>
> > st = s.split(",")
> >
> csv module again
>
> > if len(st)!= 11:
> > continue
> > else:
>
> I'm tempted to repeat the comment on reversing the conditional BUT
>
> > clas = st[10].strip()
> >
> > print ix, iy, clas
> > print >> nf, ix, iy, clas
> >
> The indentation of the print statements is not aligned with the
> previous assignment -- the effect is the same however as everything
> under the else is executed anyway.
>
> But as has also been mentioned, ignoring indentation, the apparent
> algorithm you have here is going to process every line of f2 for the
> first line of f1 -- and then for later lines in f1 it will find f2 is at
> the end of file, and do nothing. If it is supposed to process every line
> of f2 for each line of f1, you'll need to rewind f2.
>
For that I added 'Break' statement as suggested by Chris in above mails.
>
> If you mean to match one line of f1 with one line of f2, you do not
> want nested loops. But now you have to define the behavior if one of the
> two files is correct length and the other is not? Do you skip both or
> read the next line from the wrong length file? And how will you handle
> files with different numbers of records.
>
Yes , actually my Prog was like this :
for l in f1:
sp = l.split(",")
if len(sp)!= 12:
continue
else:
ix = sp[0].strip()
iy = sp[1].strip()
for s in f2:
st = s.split(",")
if len(st)!= 11:
continue
else:
clas = st[10].strip()
print ix, iy, clas
print >> nf, ix, iy, clas
break
f1.close()
f2.close()
nf.close()
I actually dont want nested loops but cant find another way to achieve what
I want, But for these files I am sure that they have equal lengths, thats
why I am taking the risk of using nested loops.. Can you suggest any
different way to go around this problem , which could be flexible and
non-errorneous ?
>
>
>
> --
> Wulfraed Dennis Lee Bieber AF6VN
> wlfr...@ix.netcom.com HTTP://wlfraed.home.netcom.com/
>
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