title: Is a hmac-sha1 hash always 20 bytes long? Python code
body: <p>Is the digest always 20 bytes long? len(hashed.digest()) seems to always be 20.    </p>
  
  <pre><code>hashed = hmac.new(key, signature_base_string, sha)
  print hashed.digest()
  print len(hashed.digest())
  i = 0
  for c in hashed.digest():
      i = i + 1
      print ord(c)
  print base64.b64encode(hashed.digest())
  </code></pre>