hmac_sha.py

#!/usr/bin/env python

# this is from The Python
# Standard Library by example
# ISBN13: 9780321767349

import hmac
import hashlib

digest_maker = hmac.new('secret-key', '', hashlib.sha1)

with open('hmac_sha.py', 'rb') as f:
    while True:
        block = f.read(1024)
        if not block:
            break
        digest_maker.update(block)

digest = digest_maker.hexdigest()
print digest