Writing your first Django app, part 2

• Django Getting started, part 2
• Writing custom django-admin commands
• Read The Docs, part 2

2-1. Admin

Lab:

(venv)$ python manage.py migrate
(venv)$ python manage.py createsuperuser
(venv)$ . go

Note

http://127.0.0.1:8000/admin/, login to maintain user/group.

2-2. Model

Lab:

*** edit mysite/settings.py
*** edit poll/models.py
*** edit poll/admin.py
*** edit go
. go

• mysite/settings.py:

  INSTALLED_APPS = [
     'polls',
     'django.contrib.admin',
     ...
  

• polls/models.py:

  from django.db import models
  
  
  class Question(models.Model):
      question_text = models.CharField(max_length=200)
      pub_date = models.DateTimeField('date published')
      def __str__(self):
          return self.question_text
  
  class Choice(models.Model):
      question = models.ForeignKey(Question, on_delete=models.CASCADE)
      choice_text = models.CharField(max_length=200)
      votes = models.IntegerField(default=0)
      def __str__(self):
          return self.choice_text
  

• polls/admin.py:

  from django.contrib import admin
  from .models import Question,Choice
  admin.site.register(Question)
  admin.site.register(Choice)
  

• go.py:

  python manage.py makemigrations
  python manage.py migrate
  python manage.py runserver
  

Note

Able to maintain Question and Choice.

2-3. Command

Lab:

*** add polls/management/commands/initpolls.py
python manage.py
python manage.py initpolls
. go

• polls/management/commands/initpolls.py:

  from django.core.management.base import BaseCommand, CommandError
  from polls.models import Question,Choice
  from django.utils import timezone
  
  class Command(BaseCommand):
      help = 'Create sample questions and choices.'
  
      def add_arguments(self, parser):
          parser.add_argument('question_num',type=int)
  
      def handle(self, *args, **options):
          q = Question.objects.all()
          q.delete()
  
          cnt = 0
          question_num = options['question_num']
          while (cnt < question_num):
              cnt += 1
              if cnt > 12:
                  self.stdout.write(self.style.WARNING('Max number was set to 12'))
                  break
              q = Question(question_text="Question #"+str(cnt),pub_date=timezone.now())
              q.save()
              q.choice_set.create(choice_text='Choice A for Question #'+str(cnt),votes=0)
              q.choice_set.create(choice_text='Choice B for Question #'+str(cnt),votes=0)
              q.choice_set.create(choice_text='Choice C for Question #'+str(cnt),votes=0)
  
          q = Question.objects.all()
          c = Choice.objects.all()
  
          self.stdout.write(self.style.SUCCESS('Questions "%s"' % q))
          self.stdout.write(self.style.SUCCESS('Choices "%s"' % c))