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if i use the code below to write a list to a file

list = (food, price, store)
data.append(list)
f = open(r"test.txt", 'a')
f.write ( os.linesep.join( list ) )


it outputs to a file like this

apple
..49
star market

and i want it to do

apple, .49. star market

any ideas

30 Dec 2005 20:22:52 -0800, <>:
> if i use the code below to write a list to a file
>
> list = (food, price, store)
> data.append(list)
> f = open(r"test.txt", 'a')
> f.write ( os.linesep.join( list ) )
>
>
> it outputs to a file like this
>
> apple
> .49
> star market
>
> and i want it to do
>
> apple, .49. star market
>
> any ideas
>

my box is windows xp, so :

>>> print repr(os.linesep)
'\r\n'

If you want to seperate them with space, you should:

f.write ( ''.join( list ) )

and list = (food, price, store)
the list is not called "list", but "tuple", a real list should be

aList = [food, price, store]
--
I like python!
My Blog: http://www.donews.net/limodou
NewEdit Maillist: http://groups.google.com/group/NewEdit

i want them to be on the same line when they are written to the file.
right now they are written like this:

food
price
store

i want them to be written like this

food price store

how do i do that?

30 Dec 2005 20:44:29 -0800, <>:
> i want them to be on the same line when they are written to the file.
> right now they are written like this:
>
> food
> price
> store
>
> i want them to be written like this
>
> food price store
>
> how do i do that?
>

>>> print ' '.join(['food', 'price', 'store'])

os.linesep represents newline.


--
I like python!
My Blog: http://www.donews.net/limodou
NewEdit Maillist: http://groups.google.com/group/NewEdit

On Fri, 30 Dec 2005 20:22:52 -0800, homepricemaps wrote:

> if i use the code below to write a list to a file
>
> list = (food, price, store)

Why are you shadowing the built in type list? This is bad practice. Sooner
or later you will do this:

list = [1, 2, 3]
something = process(list)
.... lots of code ...
# try to convert to a list
myList = list(something)

and then you'll spend ages trying to work out why list() raises an
exception.



> data.append(list)
> f = open(r"test.txt", 'a')
> f.write ( os.linesep.join( list ) )
>
>
> it outputs to a file like this
>
> apple
> .49
> star market

That's what you told it to do. Walk through the code:

>>> data = []
>>> L = ("apple", "0.49", "market")
>>> data.append(L)
>>> data
[("apple", "0.49", "market")] # a list with one tuple

So far so good. But now watch:

>>> f = open(r"test.txt", 'a')

I hope you aren't opening the file EVERY time you want
to write a single line

>>> f.write(os.linesep.join(L))

Remember what L is: ("apple", "0.49", "market"). You now join that list
(actually a tuple) into a single string: "apple\n0.49\nmarket\n" and write
that string to the file.

What happened to data? It never gets used after you append to it.


> and i want it to do
>
> apple, .49. star market

Then what you want to do is change data to a list of strings rather than
a list of tuples. Before appending to data, you join the tuple ("apple",
"0.49", "market") like so:

data.append(", ".join(L) + "\n") # note newline at the end of each line

Then, after you have appended ALL the lines, you open your file once for
writing, and write data in one go:

f.writelines(data)


Hope this helps.



--
Steven.

never mind i figured out what you were saying,. worked like a
charm!!!!!

thanks for your help.

yaffa