[Tutor] Replacing the string in a file

[Shashwat Anand]

@vanam:

If you open the file again with only '+w' and not '+rw', I guess you'll not
be getting this error  - > IOError: [Errno 22] invalid mode ('rw') or
filename: 'data.txt'

On Fri, Jan 22, 2010 at 1:51 PM, vanam <raghavendra.gv.vanam at gmail.com>wrote:

> Thanks for your mail.
>
> As you have suggested i have  changed the mode to 'rw' but it is
> throwing up an error as below
>
> *******************
> IOError: [Errno 22] invalid mode ('rw') or filename: 'data.txt'
> *******************
> I am using python 2.6.4.
>
> But Script is managed to pass with 'a+' mode/r+ mode.
>
> log = open('data.txt','r+/a+')
> for x in log:
>      x = x.replace('Python','PYTHON')
>      print x,
> log.close()
>
> It had properly written and replaced Python to PYTHON.
>
> Thanks for your suggestion.
>
>
>
> On Fri, Jan 22, 2010 at 12:42 PM, Shashwat Anand
> <anand.shashwat at gmail.com> wrote:
> > You can try it by reading all data as string, replacing the string and
> then
> > write it to target file via opeing it in +w mode.
> >
> > f = open('data.txt', 'rw').read().replace('Python', 'PYTHON')
> > f1 = open('data.txt',
> > 'w')
> > f1.write(f)
> >
> > HTH
> >
> >
> > On Fri, Jan 22, 2010 at 12:14 PM, vanam <raghavendra.gv.vanam at gmail.com>
> > wrote:
> >>
> >> Hi all,
> >>
> >> I have been trying to write a script where in it has to replace a
> >> particular string in a file and write back to the file without intact
> >> of the contents
> >>
> >> I have tried below mentioned steps, but of no avail:
> >>
> >> 1. Created a file by name data.txt and included some text (For
> >> instance,
> >>
> >> ************************************************************************
> >> Then, I started searching for a good book on Python. I couldn't find
> >> any! I did find some O'Reilly books
> >> but they were either too expensive or were more like a reference
> >> manual than a guide. So, I settled for
> >> the documentation that came with Python. However, it was too brief and
> >> small. It did give a good idea
> >> about Python but was not complete. I managed with it since I had
> >> previous programming experience, but
> >> it was unsuitable for newbies.
> >> ************************************************************************
> >>
> >> 2.Read the file contents (For this opened the file in read mode -- log
> >> = open('data.txt','r')
> >>
> >> 3.Iterated through the text using for loop for reading the contents in
> >> the file -- for x in log:
> >>
> >> 4.Replaced the word  Python with PYTHON as indicated --- x  =
> >> x.replace('Python','PYTHON')
> >>
> >> 6.printed the full contents -- It had printed the full contents by
> >> replacing the word Python to PYTHON
> >>
> >> Python string did not get changed to PYTHON for the reasons that i did
> >> not open the file in write mode and written the string
> >>
> >> [Query]: How to write Python string to PYTHON to that file without
> >> intact of the full contents
> >>
> >> I was successful in routing the contents (with changed string to
> >> PYTHON) to a different file.
> >>
> >> And i am aware that opening the file in write mode will wipe out the
> >> previous contents.
> >>
> >> I have tried appending the content which it does but that is not my
> goal.
> >>
> >>
> >> 7. Closed the files outside for loop -- log.close()
> >> --
> >> Raghavendra  Vanam
> >> _______________________________________________
> >> Tutor maillist  -  Tutor at python.org
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> >
> >
>
>
>
> --
> Raghavendra  Vanam
>
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