Help writelines

Nick Dokos nicholas.dokos at
Fri Feb 3 15:47:37 EST 2012

Anatoli Hristov <tolidtm at> wrote:

> Hi everyone,
> I`m totaly new in python and trying to figure out - how to write a list to a file with a newline at the end of each object.
> I tried alot of combinations :) like:
> users = ['toli','didi']
> fob=open('c:/Python27/Toli/username','w')
> fob.writelines(users) + '%s\N'
> fob.close()
>  or fob.writelines('\N' % users) 
> or fob.writelines('%s\N' % users)
> but nothing of dose works...
> Could you help me find out the right syntaxes?

>From the docs:

 |  writelines(...)
 |      writelines(sequence_of_strings) -> None.  Write the strings to the file.
 |      Note that newlines are not added.  The sequence can be any iterable object
 |      producing strings. This is equivalent to calling write() for each string.

So *you* need to add the newlines, e.g. you can use a list comprehension:

   fob.writelines(["%s\n" % (x) for x in users])

or write in a loop:

   for u in users:
       fob.write("%s\n" % (u))

or join the list elements together with a newline separator (but you'll
need to add a final newline by hand):

   fob.writelines("\n".join(users) + "\n")

or ...


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