from django.db import models

# Create your models here.

from datetime import datetime,timedelta

class Person(models.Model):

    name = models.CharField(max_length=100)

    birthday=models.DateTimeField()

    def __init__(self,name='welson',birthday=datetime.now()):

        self.name=name

        self.birthday=birthday

    def __str__(self):

        return self.name

    def say_hello(self):

        print("hello I am {0}".format(self.name))

python3 manage.py shell

Python 3.6.2 (v3.6.2:5fd33b5926, Jul 16 2017, 20:11:06)

[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin

Type "help", "copyright", "credits" or "license" for more information.

(InteractiveConsole)

>>> import django

>>> django.setup()

>>> from polls.models import Person

>>>

>>> p=Person()

>>> p.say_hello()

hello I am welson