Flask-Restful interupt PUT based on logic

Question

I am trying to use a preprocessor in Flask-Restless to check for a condition and if the condition is met to interrupt the PUT statement and not update the database. I've tried to del or empty the data dict but that does not seem to be working:

def pre_post(data=None, **kw):
if data['thought'] == 'test':
    data.clear()
    # Don't add to database

Doing this just adds a null to the databae