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.shash...@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.va...@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 - tu...@python.org >> To unsubscribe or change subscription options: >> http://mail.python.org/mailman/listinfo/tutor > > -- Raghavendra Vanam _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor