"""

21. Specifying 'choices' for a field

Most fields take a ``choices`` parameter, which should be a tuple of tuples

specifying which are the valid values for that field.

For each field that has ``choices``, a model instance gets a

``get_fieldname_display()`` method, where ``fieldname`` is the name of the

field. This method returns the "human-readable" value of the field.

"""

from django.db import models

GENDER_CHOICES = (

    ('M', 'Male'),

    ('F', 'Female'),

)

class Person(models.Model):

    name = models.CharField(max_length=20)

    gender = models.CharField(max_length=1, choices=GENDER_CHOICES)

    def __unicode__(self):

        return self.name