Fredrik Lundh wrote:
W. eWatson wrote:
I have an ordinary text file with a CR at the end of a line, and two
numbers in each line. Is there some way to determine the number of
lines (records) in the file before I begin reading it?
In the general case, no. A file is just a bunch of bytes. If you know
that all lines have exactly the same length, you can of course fetch the
file size and divide by the line size, but that doesn't work for
arbitrary files.
Why do you need to know the number of lines before reading it, btw?
</F>
Actually, it was a matter of curiosity, and maybe absent mindedness. I was
envisioning a program where I might want to run up and down a file a lot,
sometimes deleting a record interactively at the request of the user.
However, I wanted to keep him alert to the total number of records
remaining. However, in retrospect, I more likely do this with files in a
folder. I also want him to be able to skip around in the Win OS folder by
saying something like go forward 3 files. I'd like not to have to read all
the files between the two points. The whole idea needs some more thinking.
--
Wayne Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet
Web Page: <www.speckledwithstars.net/>
--
http://mail.python.org/mailman/listinfo/python-list
