1 from django.db import models

     2 

     3 class Author(models.Model):

     4     first_name = models.CharField(max_length=255)

     5     last_name = models.CharField(max_length=255)

     6     dob = models.DateField()

     7 

     8     def __init__(self, *args, **kwargs):

     9         super(Author, self).__init__(*args, **kwargs)

    10         # Protect against annotations being passed to __init__ --

    11         # this'll make the test suite get angry if annotations aren't

    12         # treated differently than fields.

    13         for k in kwargs:

    14             assert k in [f.attname for f in self._meta.fields], \

    15                 "Author.__init__ got an unexpected paramater: %s" % k

    16 

    17 class Book(models.Model):

    18     title = models.CharField(max_length=255)

    19     author = models.ForeignKey(Author)

    20     paperback = models.BooleanField()

    21     opening_line = models.TextField()

    22 

    23 class Coffee(models.Model):

    24     brand = models.CharField(max_length=255, db_column="name")

    25 

    26 class Reviewer(models.Model):

    27     reviewed = models.ManyToManyField(Book)

    28 

    29 class FriendlyAuthor(Author):

    30     pass