Having investigated Django 2 with Python 3 it seemed time to investigate Django 3 with Python 3, as Django 2 development ended in 2019 (Django 2 LTS will still receive bugfixes for some time yet, but no development changes).
[As my initial exercise was pretty straightforward, rather than try to update that repo, I will simply recreate the whole exercise with Django 3. For more details, please refer to the original repo.]
Note that we will use the development version of Django 3, which at the time of writing (February 2020) is 3.0.3.
This release requires Python 3.6 or more recent.
Verify the version of Python as follows:
$ python3 --version
Python 3.6.9
$[I have both Python 2 and Python 3 installed. On my system, Python 2 is python while Python 3 is python3. Likewise Python 2 uses pip while Python 3 uses pip3. In the instructions that follows I will use python3 and pip3 but these may be replaced with python and pip for systems where only Python 3 is installed.]
Install the latest version of Django (plus dependencies, if any) as follows:
$ pip3 install --user -r requirements.txt
Verify the installed version of Django as follows:
$ python3 -m django --version
3.0.3
$Use the django-admin command to do this:
$ django-admin startproject polls
And time to see if everything works so far:
$ cd polls
$ python3 manage.py runserver
The results should be something like:
$ python3 manage.py runserver
Watching for file changes with StatReloader
Performing system checks...
System check identified no issues (0 silenced).
You have 17 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.
Run 'python manage.py migrate' to apply them.
February 17, 2020 - 21:33:49
Django version 3.0.3, using settings 'polls.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
[17/Feb/2020 21:35:57] "GET / HTTP/1.1" 200 16351
[17/Feb/2020 21:35:57] "GET /static/admin/css/fonts.css HTTP/1.1" 200 423
[17/Feb/2020 21:35:57] "GET /static/admin/fonts/Roboto-Regular-webfont.woff HTTP/1.1" 200 85876
[17/Feb/2020 21:35:57] "GET /static/admin/fonts/Roboto-Bold-webfont.woff HTTP/1.1" 200 86184
[17/Feb/2020 21:35:57] "GET /static/admin/fonts/Roboto-Light-webfont.woff HTTP/1.1" 200 85692
Not Found: /favicon.ico
[17/Feb/2020 21:35:57] "GET /favicon.ico HTTP/1.1" 404 1971
^C$The development server at http://127.0.0.1:8000/ should look something like:
This needs to be done in the folder where manage.py lives:
$ python3 manage.py startapp polls_app
Open polls_app/views.py and change it as follows:
$ git diff polls_app/views.py
diff --git a/polls/polls_app/views.py b/polls/polls_app/views.py
index 91ea44a..d2dfb9f 100644
--- a/polls/polls_app/views.py
+++ b/polls/polls_app/views.py
@@ -1,3 +1,7 @@
from django.shortcuts import render
-# Create your views here.
+from django.http import HttpResponse
+
+
+def index(request):
+ return HttpResponse("Hello, world. You're at the polls index.")
$[Note that render may not be required yet, but we will leave it.]
Create a polls_app/urls.py file as follows:
from django.urls import path
from . import views # pylint: disable=relative-beyond-top-level
urlpatterns = [
path('', views.index, name='index'),
][Note the suppression of the pylint warning for the 'import views' line.]
Next update the polls/urls.py file as follows:
$ git diff polls/urls.py
diff --git a/polls/polls/urls.py b/polls/polls/urls.py
index c8c9627..9be9eec 100644
--- a/polls/polls/urls.py
+++ b/polls/polls/urls.py
@@ -14,8 +14,9 @@ Including another URLconf
2. Add a URL to urlpatterns: path('blog/', include('blog.urls'))
"""
from django.contrib import admin
-from django.urls import path
+from django.urls import include, path
urlpatterns = [
+ path('polls/', include('polls_app.urls')),
path('admin/', admin.site.urls),
]
$Again, lets check to see if everything works:
$ python3 manage.py runserver
Watching for file changes with StatReloader
Performing system checks...
System check identified no issues (0 silenced).
You have 17 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.
Run 'python manage.py migrate' to apply them.
February 17, 2020 - 22:19:57
Django version 3.0.3, using settings 'polls.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
Not Found: /
[17/Feb/2020 22:20:06] "GET / HTTP/1.1" 404 2026
^C$The polls app at http://127.0.0.1:8000/polls/ should look as follows:
The admin interface at http://127.0.0.1:8000/admin/ should look as follows:
And our development server at http://127.0.0.1:8000/ should now look like:
[END OF PART 1]
[START OF PART 2]
We will stick with the default sqlite3 database. We will also leave our timezone as UTC.
So lets run our database migrations:
$ python3 manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying auth.0010_alter_group_name_max_length... OK
Applying auth.0011_update_proxy_permissions... OK
Applying sessions.0001_initial... OK
$Now lets create our models - update polls_app/models.py as follows:
$ git diff polls_app/models.py
diff --git a/polls/polls_app/models.py b/polls/polls_app/models.py
index 71a8362..48780e6 100644
--- a/polls/polls_app/models.py
+++ b/polls/polls_app/models.py
@@ -1,3 +1,12 @@
from django.db import models
-# Create your models here.
+
+class Question(models.Model):
+ question_text = models.CharField(max_length=200)
+ pub_date = models.DateTimeField('date published')
+
+
+class Choice(models.Model):
+ question = models.ForeignKey(Question, on_delete=models.CASCADE)
+ choice_text = models.CharField(max_length=200)
+ votes = models.IntegerField(default=0)
$Now lets activate our models - update polls/settings.py as follows:
$ git diff polls/settings.py
diff --git a/polls/polls/settings.py b/polls/polls/settings.py
index c2d9e83..f7170c2 100644
--- a/polls/polls/settings.py
+++ b/polls/polls/settings.py
@@ -31,6 +31,7 @@ ALLOWED_HOSTS = []
# Application definition
INSTALLED_APPS = [
+ 'polls_app.apps.PollsAppConfig',
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
$And lets create our migrations:
$ python3 manage.py makemigrations polls_app
Migrations for 'polls_app':
polls_app/migrations/0001_initial.py
- Create model Question
- Create model Choice
$[If we wished, we could inspect our migration at this point.]
Check for issues:
$ python3 manage.py check
System check identified no issues (0 silenced).
$Apply our migrations:
$ python3 manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, polls_app, sessions
Running migrations:
Applying polls_app.0001_initial... OK
$Examine our migrations:
$ python3 manage.py showmigrations
admin
[X] 0001_initial
[X] 0002_logentry_remove_auto_add
[X] 0003_logentry_add_action_flag_choices
auth
[X] 0001_initial
[X] 0002_alter_permission_name_max_length
[X] 0003_alter_user_email_max_length
[X] 0004_alter_user_username_opts
[X] 0005_alter_user_last_login_null
[X] 0006_require_contenttypes_0002
[X] 0007_alter_validators_add_error_messages
[X] 0008_alter_user_username_max_length
[X] 0009_alter_user_last_name_max_length
[X] 0010_alter_group_name_max_length
[X] 0011_update_proxy_permissions
contenttypes
[X] 0001_initial
[X] 0002_remove_content_type_name
polls_app
[X] 0001_initial
sessions
[X] 0001_initial
$This should look as follows:
$ python3 manage.py shell
Python 3.6.9 (default, Nov 7 2019, 10:44:02)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from polls_app.models import Question, Choice
>>> Question.objects.all()
<QuerySet []>
>>> from django.utils import timezone
>>> q = Question(question_text="What's new?", pub_date=timezone.now())
>>> q.save()
>>> q.id
1
>>> Question.objects.all()
<QuerySet [<Question: Question object (1)>]>
>>> quit()
$For convenience lets add string methods to our models:
$ git diff polls_app/models.py
diff --git a/polls/polls_app/models.py b/polls/polls_app/models.py
index 48780e6..4855206 100644
--- a/polls/polls_app/models.py
+++ b/polls/polls_app/models.py
@@ -4,9 +4,13 @@ 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
$Now if we restart our API shell, we get more readable results:
$ python3 manage.py shell
Python 3.6.9 (default, Nov 7 2019, 10:44:02)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from polls_app.models import Question, Choice
>>> Question.objects.all()
<QuerySet [<Question: What's new?>]>Lets add some answers:
>>> q = Question.objects.get(pk=1)
>>> q.choice_set.all()
<QuerySet []>
>>> q.choice_set.create(choice_text='Not much', votes=0)
<Choice: Not much>
>>> q.choice_set.create(choice_text='The sky', votes=0)
<Choice: The sky>
>>> q.choice_set.create(choice_text='Taxes', votes=0)
<Choice: Taxes>
>>> q.choice_set.all()
<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Taxes>]>
>>> q.choice_set.count()
3
>>> quit()
$Lets create an Admin user:
$ python3 manage.py createsuperuser
Username (leave blank to use 'owner'): admin
Email address: admin@example.com
Password:
Password (again):
Superuser created successfully.
$[Password is 123abcde.]
Lets start the server and see if we can log in:
$ python3 manage.py runserver
Watching for file changes with StatReloader
Performing system checks...
System check identified no issues (0 silenced).
February 17, 2020 - 23:12:51
Django version 3.0.3, using settings 'polls.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
[17/Feb/2020 23:13:33] "POST /admin/login/?next=/admin/ HTTP/1.1" 302 0
[17/Feb/2020 23:13:33] "GET /admin/ HTTP/1.1" 200 3042
[17/Feb/2020 23:13:33] "GET /static/admin/css/responsive.css HTTP/1.1" 304 0
[17/Feb/2020 23:13:33] "GET /static/admin/css/dashboard.css HTTP/1.1" 200 412
[17/Feb/2020 23:13:33] "GET /static/admin/css/base.css HTTP/1.1" 304 0
[17/Feb/2020 23:13:33] "GET /static/admin/css/fonts.css HTTP/1.1" 304 0
[17/Feb/2020 23:13:33] "GET /static/admin/img/icon-changelink.svg HTTP/1.1" 200 380
[17/Feb/2020 23:13:33] "GET /static/admin/img/icon-addlink.svg HTTP/1.1" 200 331
[17/Feb/2020 23:13:33] "GET /static/admin/fonts/Roboto-Bold-webfont.woff HTTP/1.1" 304 0
^C$The logged-in interface at http://127.0.0.1:8000/admin/ should look as follows:
We need to modify polls_app/admin.py to register Question as follows:
$ git diff polls_app/admin.py
diff --git a/polls/polls_app/admin.py b/polls/polls_app/admin.py
index 8c38f3f..6af8ff6 100644
--- a/polls/polls_app/admin.py
+++ b/polls/polls_app/admin.py
@@ -1,3 +1,5 @@
from django.contrib import admin
-# Register your models here.
+from .models import Question # pylint: disable=relative-beyond-top-level
+
+admin.site.register(Question)
$[Note the suppression of the pylint warning for the 'import Question' line.]
Restart our server:
$ python3 manage.py runserver
Watching for file changes with StatReloader
Performing system checks...
System check identified no issues (0 silenced).
February 17, 2020 - 23:20:00
Django version 3.0.3, using settings 'polls.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
[17/Feb/2020 23:20:08] "GET /admin/ HTTP/1.1" 200 3749
[17/Feb/2020 23:20:08] "GET /static/admin/css/base.css HTTP/1.1" 304 0
[17/Feb/2020 23:20:08] "GET /static/admin/css/responsive.css HTTP/1.1" 304 0
[17/Feb/2020 23:20:08] "GET /static/admin/css/dashboard.css HTTP/1.1" 304 0
[17/Feb/2020 23:20:08] "GET /static/admin/css/fonts.css HTTP/1.1" 304 0
[17/Feb/2020 23:20:08] "GET /static/admin/img/icon-changelink.svg HTTP/1.1" 304 0
[17/Feb/2020 23:20:08] "GET /static/admin/img/icon-addlink.svg HTTP/1.1" 304 0
[17/Feb/2020 23:21:35] "GET /admin/polls_app/question/ HTTP/1.1" 200 4375
[17/Feb/2020 23:21:35] "GET /static/admin/css/changelists.css HTTP/1.1" 200 6190
[17/Feb/2020 23:21:35] "GET /admin/jsi18n/ HTTP/1.1" 200 3223
[17/Feb/2020 23:21:35] "GET /static/admin/js/jquery.init.js HTTP/1.1" 200 363
[17/Feb/2020 23:21:35] "GET /static/admin/js/urlify.js HTTP/1.1" 200 8941
[17/Feb/2020 23:21:35] "GET /static/admin/js/core.js HTTP/1.1" 200 5723
[17/Feb/2020 23:21:35] "GET /static/admin/js/actions.js HTTP/1.1" 200 6766
[17/Feb/2020 23:21:35] "GET /static/admin/js/admin/RelatedObjectLookups.js HTTP/1.1" 200 6918
[17/Feb/2020 23:21:35] "GET /static/admin/js/prepopulate.js HTTP/1.1" 200 1530
[17/Feb/2020 23:21:35] "GET /static/admin/js/vendor/jquery/jquery.js HTTP/1.1" 200 280364
[17/Feb/2020 23:21:35] "GET /static/admin/js/vendor/xregexp/xregexp.js HTTP/1.1" 200 128820
[17/Feb/2020 23:21:36] "GET /static/admin/img/tooltag-add.svg HTTP/1.1" 200 331
[17/Feb/2020 23:22:08] "GET /admin/polls_app/question/1/change/ HTTP/1.1" 200 5143
[17/Feb/2020 23:22:08] "GET /static/admin/js/change_form.js HTTP/1.1" 200 712
[17/Feb/2020 23:22:08] "GET /static/admin/js/calendar.js HTTP/1.1" 200 7777
[17/Feb/2020 23:22:08] "GET /static/admin/js/admin/DateTimeShortcuts.js HTTP/1.1" 200 20232
[17/Feb/2020 23:22:08] "GET /admin/jsi18n/ HTTP/1.1" 200 3223
[17/Feb/2020 23:22:08] "GET /static/admin/css/forms.css HTTP/1.1" 200 8518
[17/Feb/2020 23:22:08] "GET /static/admin/js/prepopulate_init.js HTTP/1.1" 200 495
[17/Feb/2020 23:22:08] "GET /static/admin/css/widgets.css HTTP/1.1" 200 10322
[17/Feb/2020 23:22:08] "GET /static/admin/img/icon-calendar.svg HTTP/1.1" 200 1086
[17/Feb/2020 23:22:08] "GET /static/admin/img/icon-clock.svg HTTP/1.1" 200 677
[17/Feb/2020 23:22:49] "POST /admin/polls_app/question/1/change/ HTTP/1.1" 302 0
[17/Feb/2020 23:22:49] "GET /admin/polls_app/question/ HTTP/1.1" 200 4578
[17/Feb/2020 23:22:49] "GET /admin/jsi18n/ HTTP/1.1" 200 3223
[17/Feb/2020 23:22:49] "GET /static/admin/img/icon-yes.svg HTTP/1.1" 200 436
[17/Feb/2020 23:22:53] "GET /admin/polls_app/question/1/change/ HTTP/1.1" 200 5143
[17/Feb/2020 23:22:53] "GET /admin/jsi18n/ HTTP/1.1" 200 3223
[17/Feb/2020 23:22:55] "GET /admin/polls_app/question/1/history/ HTTP/1.1" 200 2329
[17/Feb/2020 23:23:47] "GET /admin/polls_app/question/1/change/ HTTP/1.1" 200 5143
[17/Feb/2020 23:25:30] "GET /admin/logout/ HTTP/1.1" 200 1207
^C$And if we refresh our browser window we should get:
And now we can edit our Question:
And we even get a modification history:
[END OF PART 2]
Finally, lets run everything through black, which should look roughly like the following:
$ black .
reformatted /home/martin/Documents/Django/Writing_Django_3/polls/polls/asgi.py
reformatted /home/martin/Documents/Django/Writing_Django_3/polls/manage.py
reformatted /home/martin/Documents/Django/Writing_Django_3/polls/polls/urls.py
reformatted /home/martin/Documents/Django/Writing_Django_3/polls/polls/wsgi.py
reformatted /home/martin/Documents/Django/Writing_Django_3/polls/polls_app/apps.py
reformatted /home/martin/Documents/Django/Writing_Django_3/polls/polls/settings.py
All done! ✨ 🍰 ✨
6 files reformatted, 7 files left unchanged.
$- Django 3.0.3
- Python 3.6.9
- Follow parts 3 - 7 of this tutorial
- Add a badge for
Blackformatting style
Part 1:
http://docs.djangoproject.com/en/3.0/intro/tutorial01/
Part 2:
http://docs.djangoproject.com/en/3.0/intro/tutorial02/