File read from stdin and printed to temp file are not identicial?

[Jean Luc Truchtersheim]

Hello,

I am trying to read from stdin and dump what's read to a temporary
file. My code works for small files but as soon as I have a file that
has, e.g., more than 300 lines, there is always one and only one line
that is truncated compared to the input.

Here is my code:
#---------------------------------------------------------------------------------
#! /usr/bin/env python

import sys
from tempfile import *

if __name__ == "__main__":
	data = []
	f_in = NamedTemporaryFile(suffix=".txt", delete=False)
	for line in sys.stdin:
		f_in.write(line)
		data.append(line)
	f_in.close
	f = open(f_in.name, 'rb')
	i=0
	for line in f:
		if data[i] != line:
			print >>sys.stderr, "line %d:\nfile(%d):\"%s\"\narray(%d):\"%s\"" %
(i+1, len(line), line, len(data[i]), data[i])
		i += 1
	sys.exit()
#-------------------------------------------------------------------------------------------------

I feel that I must be doing something very stupid, but I don't really
know what.

Any idea?

Can anybody reproduce this behavior.

Thanks a bunch for any help.

Jean Luc.