Before you start this assignment, you should already have signed up for a PythonAnywhere account and be logged in on your account. You should be able to complete all of the exercises in this course using a free PythonAnywhere account.
You can view a video walkthrough of this assignment.
Note: If you are submitting these assignments to the auto grader you should complete each assignment and then submit it and get full credit before moving on to the next assignment. Because the assignments build on one another the application that you have build by the last step of the tutorial will no longer pass the earlier autograders.
Once you have created your PYAW account, start a
and set up a virtual environment with Python 3.x and Django 4.
mkvirtualenv django4 --python=/usr/bin/python3.9 pip install django==4.0.7 ## this may take a couple of minutes
Note if you exit and re-start a new shell on PythonAnywhere - you need the following command to get back into your virtual environment in the new bash shell.
Lets make sure that your django was installed successfully and you are running the rght version of Python with the following commands:
python --version # This should show something like Python 3.9.5 python -m django --version # This should show something like 4.0.7
Lets also get a copy of the sample code for DJ4E checked out so you can look at sample code
as the course progresses and install some important additional Django software libraries using
cd ~ git clone https://github.com/csev/dj4e-samples cd dj4e-samples pip install -r requirements4.txt python3 manage.py check
This is the normal output of running
When you want to use social login, please see dj4e-samples/github_settings-dist.py Using registration/login.html as the login template System check identified no issues (0 silenced).
check identifies errors, do not go on to the rest of the assignment
once you can run
check and there are no errors. If you see this error:
python manage.py check File "manage.py", line 17 ) from exc ^ SyntaxError: invalid syntax
Do not edit your
manage.py file - the problem is never in that file.
There are several possible reasons for this:
It can mean that you are not running in the virtual environment (
workon django4) and mistakenly
running Python 2 instead of Python 3. There is no error in
manage.py - it is valid
Python 3 syntax that confuses Python 2.
manage.pyfile and have introduced a syntax error. Take a look at this screen shot of a working manage.py and check if there are any differences. While you are there you can change line 1 from 'python' to 'python3' and the syntax error indication will go away. Often the mistakes are on the indentation of lines 16 and 17. Check and match the indentation in the screen shot exactly.
check works do:
python3 manage.py makemigrations
This is the normal output of the
When you want to use social login, please see dj4e-samples/github_settings-dist.py Using registration/login.html as the login template No changes detected
python3 manage.py migrate
If you are doing this for the first time, it should run some migrations and create a file
dj4e-samples folder is reference material that you can
use through out the course. From time to
time we might make changes to this and ask you to do a
git pull to get the latest version
of the code.
Now that we have your Django set up and you have retrieved the sample code for DJ4E, lets build your first application in the PYAW shell:
cd ~ mkdir django_projects cd django_projects django-admin startproject mysite
You need to edit the file
~/django_projects/mysite/mysite/settings.py and change
the allowed hosts line (around line 28) to be:
ALLOWED_HOSTS = [ '*' ]
Leave the DEBUG value set to True - we are not really "in production" and if you set this to False you will not see error messages when you make mistakes.
There are three ways to edit files in your PythonAnywhere environment, ranging from the easiest to the coolest. You only have to edit the file one of these ways.
(1) Go to the main PythonAnywhere dashboard, browse files, navigate to the correct folder and edit the file
(2) Or in the command line:
cd ~/django_projects/mysite/mysite/ nano settings.py Save the File by pressing 'CTRL-X', 'Y', and Enter
(3) Don't try this most difficult and most cool way to edit files on Linux without a helper
if it is your first time with the
vi text editor.
cd ~/django_projects/mysite/mysite/ vi settings.py
Once you have opened
vi, cursor down to the
position your cursor between the braces and press the
i key to go into 'INSERT' mode, then type your new text and press the
esc key when you are
done. To save the file, you type
:wq followed by
enter. If you get lost press
enter to get out of the file without saving.
If you aleady know some other command line text editor in Linux, you can use it to edit files. In general, you will find that it often quicker and easier to make small edits to files in the command line rather than a full screen UI. And once you start deploying real applications in production environments like Google, Amazon, Microsoft, etc.. all you will have is command line.
Now that we have built your first application, we need to tell PythonAnywhere where to look to run your application as a web server so you can test it.
In the PYAW web interface navigate to the
Web tab to create a new web application. You do not need
to upgrade your account - they give you one application like drchuck.pythonanywhere.com - use this
free application for the course.
When making the new application, do not create a "Django application" - instead,
manual configuration and Python 3.9. Once the webapp is created, you need to
make a few changes to the settings for the web app and your application.
Source code: /home/drchuck/django_projects/mysite Working directory: /home/drchuck/django_projects/mysite Virtualenv: /home/drchuck/.virtualenvs/django4
drchuck with your account on PythonAnywhere.
Note that once you have your Virtualenv set up you have a very convenient link titled "Start a console in this virtualenv" - this is a great way to open up consoles so you never have to type "workon django4" and it makes sure your virtual envronment is properly set up and configured. Sample image
Then edit the WGSI Configuration File and put the following code into it. Make sure to delete the existing content of the WGSI Configuration File file and completely replace it with the text below. This is slightly different from the sample in the PythonAnywhere tutorial.
import os import sys path = os.path.expanduser('~/django_projects/mysite') if path not in sys.path: sys.path.insert(0, path) os.environ['DJANGO_SETTINGS_MODULE'] = 'mysite.settings' from django.core.wsgi import get_wsgi_application from django.contrib.staticfiles.handlers import StaticFilesHandler application = StaticFilesHandler(get_wsgi_application())
Once the above configuration is complete, go back to the top of the PYAW
Reload your web application, wait a few seconds and check
that it is up and visiting the URL for your application shown in in the Web
tab on PYAW like:
Here is a Sample of what the resulting page should look like.
Just as a note, you never run the
runserver command on PythonAnywhere.
python3 manage.py runserver
If you try to do
runserver on PythonAnywhere it, you will see an error message like this
00:26 ~/django_projects/mysite (master)$ python manage.py runserver Watching for file changes with StatReloader Performing system checks... System check identified no issues (0 silenced). September 14, 2021 - 00:26:16 Django version 2.2.7, using settings 'mysite.settings' Starting development server at http://127.0.0.1:8000/ Quit the server with CONTROL-C. Error: That port is already in use. 00:26 ~/django_projects/mysite (master)$
This will never work on PythonAnywhere. You run / restart your server on
PythonAnywhere using the "reload" button on your
Web tab. So
if you are reading any Django instructions that say to do a
runserver, instead do a
check and then reload the application in the PythonAnywhere web UI.
At this point, you can add the polls application from the first Django tutorial. We are jumping into the middle of this tutorial because the first part of the tutorial is installing and configuring Django in general.
The first step is to make the
cd ~/django_projects/mysite python3 manage.py startapp polls
Continue to follow the steps outlined in Django tutorial. until you reach the part where the tutorial tells you to run this command:
python3 manage.py runserver # <-- Never run this on pythonanywhere
Do not run the
runserver command on PythonAnywhere. Instead run the following command:
python3 manage.py check
check does a check for syntax and logic errors in your Django application.
It is easier to fix errors in the command line.
And when there are no errors, you are done with the Django Tutorial, come back to these
instructions - and navigate to the
Web tab in Python anywhere
Reload your application and then test your application by navigating to:
You should see a line that looks like:
Hello, world. You're at the polls index.
Going forward, every time we make changes to our application, we should run
python3 manage.py check
in the shell, and when that shows no errors, navigate to the
and then go to your web site to test your changes. This pattern of change, reload, and test
will become second nature after a while.
If your application passed a
check but fails to
load or reload, you might get an error message that looks
If you get an error, you will need to look through the error logs
Web tab on PythonAnywhere:
First check the
error log and then check the
Make sure to scroll through the logs to the end to find the most recent error.
For some reason students who finish this assignment often end up making their
mysite folder twice.
They end up with a folder in their home directory and in their
It is a good idea to remove the extra folder in your home directory after making sure that the right
code is in your
django_projects/mysite folder. It is really frustrating to have two folders and
do a bunch of work in one of the folders that does not actually affect your running application.
So you might as well clean this up right away if you see it.
You may get lots of errors when you run
manage.py - the errors are never
in the file itself and you will never need to edit
manage.py to fix a problem
with your program.
Sometimes if you run
python manage.py ....
Sometimes it even says there is a syntax error in
manage.py like this:
$ python manage.py check File "manage.py", line 16 ) from exc ^ SyntaxError: invalid syntax
This is because you are running python 2.x and not python 3.x. The file is not valid syntax for python2. If you are runing python2, it probably means you are not in the correct virtual environment. If you check the python version:
$ python --version Python 2.7.12
And it is 2.x, you have bigger problems that need to be fixed first.
If you open
manage.py in the file editor, it will show a syntax error on line
16 - this is because it is looking at the file as Python 2 (sound familiar).
If this bothers you, you can change the first line of the file (change nothing else)
This is called the "Hashbang" and is a specially formatted comment that indicates what kind of code the file contains.
And if you are reading this after you made a mistake and edited your
manage.py - here
is a fresh copy of the file you can use:
Fresh copy of manage.py
In general Django 4.x is quite compatible with Django 3.x and Django 2.x. You might find
small errors if you started a project on an earlier version of Django and upgraded to
Django 4.x mid-project. One common error is that the
url() feature used in various
files changed form 3.x to 4.x. If you see something like the following error:
from django.conf.urls import url ImportError: Cannot import 'url' from 'django.conf.urls'
It is quite easy to fix. The 'url()' function is now renamed and moves into a different
area of the Django library in 4.x. Remove the above line and find an import from
and add a
re_path to it like the following:
from django.urls import include, path, re_path ^^^^^^^ Add this
Then find lines that call
url( .. and change them to be
re_path( ... - the calling
patterns are the same between
re_path so no other changes are needed.
The good news is that
re_path also works with the Django 3.x library so once you make
the change you don't have to undo the change when going back to Django 3.x.
Here is a StackOverflow answer
that covers this topic. It actually shows two ways to fix this - but the cleaner and more future-proof
approach is just changing to use
re_path as shown above.
If you have followed instructions and it just does not work and you want to start over at the beginning of this assignment, here are the steps to clear things out:
Remove all of your running consoles under the www.pythonanywhere.com Consoles tab
Open a new bash console from the Consoles tab. Do not run the workon command and run the following commands:
cd ~ rm -rf .virtualenvs/django4 rm -rf dj4e-samples rm -rf django_projects
Then close your console, and delete it under the Consoles tab and go up to the very beginning of this handout and start over.
We did not remove any of the configuration changes under the Web tab - so as you re-create all the files, parts of the Web tab may just start working when you Reload your application.