title: Python-Eve: Use Pre-Request Event Hooks to modify data before inserting to DB
body: <p>I am adding new data into my Database by doing a POST-request on my eve-API.
  Since there need to be added some data from the Python side I thought I could add these data by using a <a href="http://python-eve.org/features.html#pre-request-event-hooks" rel="nofollow">pre-request event hook</a>.</p>
  
  <p>So is there a way to modify the data contained in the POST-request using a pre-request hook before inserting the data into the database? I already understood how to implement such a hook but do not have any clue about how to modify data before inserting to DB.</p>