def flag_modified(instance, key):
 (state, dict_) = (instance_state(instance), instance_dict(instance))
 impl = state.manager[key].impl
 state._modified_event(dict_, impl, NO_VALUE, force=True)

def flag_modified ( instance , key ) : ( state , dict_ ) = ( instance_state ( instance ) , instance_dict ( instance ) ) impl = state . manager [ key ] . impl state . _modified_event ( dict_ , impl , NO_VALUE , force = True )
mark an attribute on an instance as modified .