> 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...
Anatoli Hristov <toli...@gmail.com> 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):
> 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?
> Thanks
mylist.writelines() is a shorthand for a loop of writes, once per list item. It does not append a newline, since if the list had come from readlines(), it would already have the linefeed on each line.
So you have a few choices. You could add a newline to each list item before issuing the writelines(), or write your own loop. I vote for writing your own loop, since there may be other things you want to change on each line.
1)
users = [item+"\n" for item in users] # add a newline to each item
2)
for line in users:
fob.write(line + "\n")
fob.close()
There are other possibilities, such as
contents = "\n".join(mylist) #make a single string out of it
fob.write(contents + "\n") #note we had to add one at the very end,
#because join just puts the separator between items, not after them.
