Reading and Writing

[elias.goodman@gmail.com]

I am new to Python and programming. I am looking for some basic
instruction here.

How should I: Open a Text file, read from it, modify it, print to
another .txt?

For instance: Read a string, sort it, write the sorted string.

I understand the algorithms but I don't know the actual mechanics of
Python.

Any help or advice as to where to look would be great.

Thanks.

[Sir Galahad the chaste]

Re: Reading and Writing

Hi,

elias.goodman@g mail.com wrote:[color=blue]
> How should I: Open a Text file, read from it, modify it, print to
> another .txt?
>
> For instance: Read a string, sort it, write the sorted string.[/color]

What do you mean by "sorting"? If you want to sort the lines contained
in a file, you could do something like this.

$ cat in.txt
foo
bar
baz
ham
spam
$ cat process.py
#!/usr/bin/env python
lines = open("in.txt"). readlines()
lines.sort()
out = open("out.txt", "w")
for line in lines:
out.write(line)
out.close()
$ python process.py
$ cat out.txt
bar
baz
foo
ham
spam

Regards
G.

[Novitiate]

Re: Reading and Writing

-Galahad,

Thank you very much. I will give it a shot and see if I can make it
hapen. I think this will help a lot.

I was just trying to implement a simple sorting algorithm that I knew
from C++, for practice but I couldn't figure the mechanics of Python.
Thanks again,

Novitiate

[Novitiate]

Re: Reading and Writing

-Galahad,

Thank you very much. I will give it a shot and see if I can make it
hapen. I think this will help a lot.

I was just trying to implement a simple sorting algorithm that I knew
from C++, for practice but I couldn't figure the mechanics of Python.
Thanks again,

Novitiate

[Mike Meyer]

Re: Reading and Writing

Sir Galahad the chaste <sttmjoc0@fastm ail.fm> writes:
[color=blue]
> Hi,
>
> elias.goodman@g mail.com wrote:[color=green]
>> How should I: Open a Text file, read from it, modify it, print to
>> another .txt?
>> For instance: Read a string, sort it, write the sorted string.[/color]
>
> What do you mean by "sorting"? If you want to sort the lines contained
> in a file, you could do something like this.
>
> $ cat in.txt
> foo
> bar
> baz
> ham
> spam
> $ cat process.py
> #!/usr/bin/env python
> lines = open("in.txt"). readlines()[/color]

Some people consider it bad style to leave opened files lieing around,
so this shold be:

f = open("in.txt")
lines = f.readlines()
f.close()
[color=blue]
> lines.sort()
> out = open("out.txt", "w")
> for line in lines:
> out.write(line)[/color]

Those two should be
out.writelines( lines)
[color=blue]
> out.close()[/color]

<mike
--
Mike Meyer <mwm@mired.or g> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.