def __get__(self, instance, owner):
        """Descriptor for retrieving a value from a field in a Model."""
        # Check if Model class is being called, rather than Model instance
        if instance is None:
            return self
        # Get value from Model instance if available
        value = instance._values.get(self.name)
        # If value is None or empty string then return the default value, if set
        # if value in [None, ''] and self.default is not None:
        #     return self.default
        return value
def __get__ ( self , instance , owner ) : if instance is None : return self value = instance . _values . get ( self . name ) return value
Descriptor for retrieving a value from a field in a Model.