def _is_initialized ( self , entity ) : return ( not self . _required or ( ( self . _has_value ( entity ) or self . _default is not None ) and self . _get_value ( entity ) is not None ) )
check if a property is null python
Internal helper to ask if the entity has a value for this Property .
def _is_initialized(self, entity):
    """Internal helper to ask if the entity has a value for this Property.

    This returns False if a value is stored but it is None.
    """
    return (not self._required or
            ((self._has_value(entity) or self._default is not None) and
             self._get_value(entity) is not None))