Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!ecngs!feeder2.ecngs.de!newsfeed.freenet.ag!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.002 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; '16,': 0.03; 'raises': 0.07; 'subject:Error': 0.07; 'subject:file': 0.07; '"w")': 0.09; 'cc:addr:python-list': 0.10; 'subject:python': 0.11; '>>': 0.16; 'csv': 0.16; 'return,': 0.16; 'subject:CSV': 0.16; 'subject:writing': 0.16; 'to:addr:pearwood.info': 0.16; 'to:addr:steve+comp.lang.python': 0.16; "to:name:steven d'aprano": 0.16; 'true:': 0.16; 'mon,': 0.16; 'wrote:': 0.17; 'feb': 0.19; 'trying': 0.21; 'import': 0.21; '"",': 0.22; 'cc:2**0': 0.23; '>': 0.23; 'cc:addr:python.org': 0.25; 'header:In-Reply-To:1': 0.25; '(most': 0.27; '???': 0.27; 'message-id:@mail.gmail.com': 0.27; "d'aprano": 0.29; 'steven': 0.29; 'skip:& 10': 0.29; 'error': 0.30; 'file': 0.32; 'could': 0.32; 'print': 0.32; '11,': 0.33; 'traceback': 0.33; 'skip:& 20': 0.33; 'received:google.com': 0.34; 'pm,': 0.35; 'there': 0.35; 'but': 0.36; 'data.': 0.36; 'anything': 0.36; 'possible': 0.37; 'does': 0.37; 'two': 0.37; 'why': 0.37; 'subject:: ': 0.38; 'files': 0.38; 'some': 0.38; 'nothing': 0.38; 'end': 0.40; 'skip:w 30': 0.61; 'reached': 0.65; 'programme': 0.69; '11:': 0.84; '12:': 0.84; '2013': 0.84; 'theirs': 0.84 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=BmXqhkCjaiIeqaVOVtWMA5IS7mIWsWEmxCi5xshb/R4=; b=ChqyXuBAzUtjGKaULThLdtG5hKqwZiJxb2USQ5GA/NiDYO230MMST1NwfHhiH/D3UP S7fiYEp05JucTBSgJMl9qVerJaNtqs5blVXdnBnTJp2+CzK9RC/TQPUduHT8SS9SVw9f gsNR5wvhppETTV4AEg9X9zMC4bKePtXdRSv9BWyxpa+JEiwp686YBQtaTQn0ZOJXbUM9 i6Cex7H1VzKRJ5MQZ5fpa/sTskrGbS7yQVUALYb41Y1wqyYuygOo3AeITfZG+NIZbnOg pNkIAu1knT2cDMFWvo1J/NAFRfeCwnqfz5s9pbEajtLc8NT+4yhMSN/zIQRD4S01OtpS GgmA== MIME-Version: 1.0 X-Received: by 10.50.196.227 with SMTP id ip3mr11410320igc.97.1360586640362; Mon, 11 Feb 2013 04:44:00 -0800 (PST) In-Reply-To: <5118e383$0$29985$c3e8da3$5496439d@news.astraweb.com> References: <5118e383$0$29985$c3e8da3$5496439d@news.astraweb.com> Date: Mon, 11 Feb 2013 13:44:00 +0100 Subject: Re: Error in reading and writing CSV format file in python From: inshu chauhan To: "Steven D'Aprano" Content-Type: multipart/alternative; boundary=14dae934117b628eca04d572432a Cc: "python-list@python.org" X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 158 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1360586648 news.xs4all.nl 6876 [2001:888:2000:d::a6]:42156 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:38672 --14dae934117b628eca04d572432a Content-Type: text/plain; charset=ISO-8859-1 On Mon, Feb 11, 2013 at 1:26 PM, Steven D'Aprano < steve+comp.lang.python@pearwood.info> wrote: > inshu chauhan wrote: > > > In the programme below I am trying to read two csv format files and > > process them and write a new file with some of theirs data. > > > > import csv > > f1_reader = csv.reader(open(r"Z:\Weka > > work\Feature_Vectors_Fullset_00.arff")) > > f2_reader = csv.reader(open(r"Z:\Weka > > work\Feature_Vectors_Fullset_00_noxy+class.arff")) > > nf = open(r"Z:\Weka work\classified_image00_withoutxy.arff", "w") > > > > while True: > > l1 = f1_reader.next() > > while len(l1) != 12: > > l1 = f1_reader.next() > > l2 = f2_reader.next() > > while len(l2) != 11: > > l2 = f2_reader.next() > > > > ix = l1[0].strip() > > iy = l1[1].strip() > > classification = l2[8].strip() > > > > print >> nf, ix, iy, classification > > > > nf.close() > > > > This programme is giving me this error now : > > > > Traceback (most recent call last): > > File "Z:\Weka work\final_image_classificationwithoutxy.py", line 16, in > > > > l2 = f2_reader.next() > > StopIteration > > > > > > what could be a possible reason to StopIteration ??? > > next() raises StopIteration when there is nothing else to return. > > > py> it = iter([1, 2, 3]) > py> it.next() > 1 > py> it.next() > 2 > py> it.next() > 3 > py> it.next() > Traceback (most recent call last): > File "", line 1, in > StopIteration > > > You have reached the end of the file and there is nothing else for the CSV > reader to return, so it raises StopIteration. > But why does it has nothing to return so early before traversing the whole file ? Is there any way it can be corrected ? And also the programme isn't writing anything to the file ? > > > --14dae934117b628eca04d572432a Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

= On Mon, Feb 11, 2013 at 1:26 PM, Steven D'Aprano <= s= teve+comp.lang.python@pearwood.info> wrote:
insh= u chauhan wrote:

> In the programme below I am trying to read two csv format files and > process them and write a new file with some of theirs data.
>
> import csv
> f1_reader =3D csv.reader(open(r"Z:\Weka
> work\Feature_Vectors_Fullset_00.arff"))
> f2_reader =3D csv.reader(open(r"Z:\Weka
> work\Feature_Vectors_Fullset_00_noxy+class.arff"))
> nf =3D open(r"Z:\Weka work\classified_image00_withoutxy.arff"= ;, "w")
>
> while True:
> =A0 =A0 l1 =3D f1_reader.next()
> =A0 =A0 while len(l1) !=3D 12:
> =A0 =A0 =A0 =A0 l1 =3D f1_reader.next()
> =A0 =A0 l2 =3D f2_reader.next()
> =A0 =A0 while len(l2) !=3D 11:
> =A0 =A0 =A0 =A0 l2 =3D f2_reader.next()
>
> =A0 =A0 ix =3D l1[0].strip()
> =A0 =A0 iy =3D l1[1].strip()
> =A0 =A0 classification =3D l2[8].strip()
>
> =A0 =A0 print >> nf, ix, iy, classification
>
> nf.close()
>
> This programme is giving me this error now :
>
> Traceback (most recent call last):
> =A0 File "Z:\Weka work\final_image_classificationwithoutxy.py&quo= t;, line 16, in
> <module>
> =A0 =A0 l2 =3D f2_reader.next()
> StopIteration
>
>
> what could be a possible reason to StopIteration ???

next() raises StopIteration when there is nothing else to retur= n.


py> it =3D iter([1, 2, 3])
py> it.next()
1
py> it.next()
2
py> it.next()
3
py> it.next()
Traceback (most recent call last):
=A0 File "<stdin>", line 1, in <module>
StopIteration


You have reached the end of the file and there is nothing else for the CSV<= br> reader to return, so it raises StopIteration.


But= why does it has nothing to return so early before traversing the whole fil= e ? Is there any way it can be corrected ?=A0 And also the programme isn= 9;t writing anything to the file ?



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