tests/sha256line.py

httppeer: avoid another bad reference before assignment warning

This wasn't a problem, because `b''` from the `AttributeError` handler is in
`bundle2.bundletypes`, so the following loop and conditional always run at least
once.  But PyCharm can't figure that out on its own, and it took a little
exploring to figure out it wasn't a problem.  The usage in `bundle2.writebundle`
is to look it up in the map of bundle types, so it will break in a more obvious
way in the unlikely event that the empty string is removed from the map in the
future.

#!/usr/bin/env python3
#
# A tool to help producing large and poorly compressible files
#
# Usage:
#   $TESTDIR/seq.py 1000 | $TESTDIR/sha256line.py > my-file.txt


import hashlib
import sys


for line in sys.stdin:
    print(hashlib.sha256(line.encode('utf8')).hexdigest())