Django - Model fields

django_model.py

from django.db import models
from datetime import datetime
import Pet, Car


# Reference: https://docs.djangoproject.com/en/2.2/ref/models/fields/#choices

COUNTRIES = (
    ('ES', 'SPAIN'),
    ('FR', 'FRANCE'),
    ('UK', 'UNITED KINGDOM'),
    ('GR', 'GERMAN'),
)

class People(models.Model):
    name = models.CharField(max_length=50, blank=True, null=True)
    picture = models.TextField(blank=False, null=False) # Base64
    description = models.TextField(blank=True, null=True) 
    salary = models.IntegerField(blank=False, null=False, default=0)
    register_at = models.DateTimeField(default=datetime.now)
    birthdate = models.DateField(blank=False, null=False)
    country = models.CharField(max_length=2, choices=COUNTRIES)


    friends = models.ManyToManyField(People, blank=True, null=True, on_delete=models.CASCADE)
    pet = models.ForeignKey(Pet, blank=False, null=False, on_delete=models.CASCADE related_name='pets')
    car = models.OneToOneField(Car, blank=True, null=True, on_delete=models.CASCADE)