\r\n or \n notepad editor end line ???

[Peter Hansen]

Steven D'Aprano wrote:
> So going back to the original question... if I open in "r" mode a text
> file which was created under Windows, I will get \r characters in the
> text and have to deal with them regardless of what platform I am running
> Python under. Correct?

Almost, but the way you phrased that makes it incorrect in at least one 
case.  I suspect you are clear on the actual situation now, but just to 
correct your wording: you will get \r characters and have to deal with 
them on any platform which does *not* use \r\n for its line endings. 
(Under Windows, of course, you won't have to deal with them at all.)

> If I use "rU" mode Python suppress the \r characters. When I write a
> string back, I'm responsible for making sure the EOL markers are correct
> for whatever platform I expect the file to be read under. Unless Python
> can somehow magically read my mind and know that even though I'm writing
> the file under Linux it will be read later under Windows. Am I close?

Python can't magically read your mind, although if you manage to steal 
the time machine (in the future) you could always just come back and fix 
the files as they are written, and you (in present time) would *think* 
that Python had magically read your mind...

A few more trinkets: some programs on Windows will work just fine even 
if they encounter files with only \n line endings.  Decent text editors 
will either adapt or let you specify what line ending should be 
expected.  Trying always to work with only \n line endings in files you 
write will help us move towards the day when we can obliterate the 
abomination that is \r\n so try it out and use "rU" to read, "w" to 
write on Linux if that works in your case.

-Peter