Which format should I save my python script output?

Question

I have an executable (converted to exe from python using py2exe) that outputs lists of numbers that could be from 0-50K lines long or a little bit more. While developing, I just saved them to a TXT file using simple f.write. The person wants to print this output on paper! (don't ask why lol)

So, I'm wondering if I can output it to something like HTML? XML? Something that could display tables of 50K lines and maybe 3 columns and that would also run in any PC without additional programs? Suggestions?

EDIT:
Regarding CSV:
In most situations the best way in my opinion would be to make a CSV. I'm not opposing it in anyway, rather I think others might find Lott's answer useful for their cases. Sorry I didn't explain it that well in my question as far as my constraints go.
My constraints are: the user doesn't have an office suite, no python installed. Just think of a PC that has the bare minimum after a clean windows xp/vista installation, maybe Internet Explorer 7 or 8. This PC has to be able to open my output file and allow for reasonable viewing, searching, and printing.

Answer 1

You could use LaTeX to produce a PDF, maybe? But why exactly isn't a text file good enough?

Answer 2

CSV.

http://docs.python.org/library/csv.html

http://en.wikipedia.org/wiki/Comma-separated_values

They can load a spreadsheet and print anything they want.

Answer 3

You can produce a PDF using Reportlab. After all if you really want full control of the printed output, there's nothing that beats PDF.

Answer 4

If you can't install anything on the computer, the you might be best off outputting an HTML file with the data in a <table> that the user could view/search/print in IE.

Answer 5

Does 50k lines make too large a file? If not, just continue writing text files. Otherwise an easy solution would be to continue spitting out text files and compress them, e.g. with zip. You could use the zipfile library in Python. Most computers have no trouble reading zip files.