model_from_db.py

class Model(metaclass=ModelBase):
  
    # ...

    @classmethod
    def from_db(cls, db, field_names, values):
        if len(values) != len(cls._meta.concrete_fields):
            values_iter = iter(values)
            values = [
                next(values_iter) if f.attname in field_names else DEFERRED
                for f in cls._meta.concrete_fields
            ] # values is a tuple ('Yu', 'Chen', '123')
        new = cls(*values) # new is a Student instance with attributes initialized like a regular Python instance