Method get_prep_value

django/db/models/fields/__init__.py:1030–1034

Perform preliminary non-db specific value checks and conversions.

(self, value)

        return getattr(model_instance, self.attname)

    def get_prep_value(self, value):
        """Perform preliminary non-db specific value checks and conversions."""
        if isinstance(value, Promise):
            value = value._proxy____cast()
        return value

    def get_db_prep_value(self, value, connection, prepared=False):
        """