How to use writelines to append new lines to an existing file

Grigoris Tsolakidis gcholakidis at hotmail.com.spam-remove
Thu Sep 22 09:02:45 EDT 2005


Use
file = open(open('/tmp/myfile', 'a')) the second time
when you want to append line

"Nico Grubert" <nicogrubert at gmail.com> wrote in message 
news:mailman.781.1127393534.509.python-list at python.org...
> Hi there,
>
> I would like to open an existing file that contains some lines of text in 
> order to append a new line at the end of the content.
>
> My first try was:
>
> >>> f = open('/tmp/myfile', 'w') #create new file for writing
> >>> f.writelines('123')      #write first line
> >>> f.close()
> >>> f = open('/tmp/myfile', 'w') #open existing file to append new line
> >>> f.writelines('456')
> >>> f.close()
> >>> f = open('/tmp/myfile', 'r') # open file for reading
> >>> f.read()
> '456'
>
> I supposed to have:
> >>> f.read()
> '123\n456\n'
>
>
> Does  f = open('/tmp/myfile', 'w')  overwrite the existing file or does 
> f.writelines('456') replace the first line in the existing file?
>
> Nico 





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