title: hash string size
body: <p>In python I use the following code to create hash for user passwords:</p>
  
  <pre><code>self.password = hmac.new(security_key, raw_password, sha1).hexdigest()
  </code></pre>
  
  <p>Now I'd like to save this value to database. What size must be my database column? 
  It seems related to digest_size property, but do not know what object or class has such property. sha1 doesn't have one.</p>