../

hosting Python web app on PythonAnywhere

Konstantinos Foutzopoulos

PythonAnywhere is a simple-to-use (WSGI-based) hoster for Python web apps that has a free tier. It makes an excellent platform for anyone wanting to quickly test an app they’re making. For, mainly personal but potentially useful to someone else, reference the steps to upload and run a locally developed project are the following. Replace user with own username and mysite with some other name if want to.

Upload project

  • Archive the project directory. Can use the command zip -r mysite.zip mysite/. If it is a git repo it can be archived with git archive --format zip --output mysite.zip master. The later will require generating or uploading independently any files not commited such as SQLite database files.

  • Upload the archive in the Files tab.

  • Open a bash console on home by the link right of path in the Files tab. Preferably in new tab.

  • Extract the archive with unzip mysite.zip -d mysite if archive was made with git archive. Else first extract to temp directory with unzip mysite.zip -d tempdir and move accordingly. If zip command in first step was used do mv tempdir/mysite mysite.

This is one of the options in documentation. The others will be upload to code share site such as GitHub and saner ones, available only to paying accounts, sftp and rsync options.

Set virtual environment

The simplest approach to this will be to upload an archive of the environment directory similar to what was done for project. Can extract to /home/user/venv and then set this path to the following section.

The more correct approach will be:

  • Export environment configuration with pip freeze > requirements.txt in project directory.

  • Make a new virtual environment with mkvirtualenv myvenv. The mkvirtualenv is not just a tool but a project consisting of a collection of handy wrappers to virtualenv tool for managing virtual environments that PythonAnywhere has preinstalled.

    After creating it, the environment is activated automatically. In case it needs to be accessed afterwards the command workon myvenv can be used.

  • Enter the project directory and install requirements with pip install -r requirements.txt.

Paying accounts also have the option to run those commands in an ssh session.

Set app

  • Visit the Web tab and add a new web app from left sidebar. PythonAnywhere provides some options but those create a new project and require manual intervetion to run a local project. Rather just select the manual option.

  • Edit the source code link in the Code section to the directory containing the uploaded code. If previous steps have been followed this will be /home/user/mysite.

  • Replace the contents in wsgi.py file. This is project-dependent and default file has instructions to what to edit it to for Django and Flask.

For Flask project, it’s required just to import app as application, as done in run.py, but not run it.

import sys
path = '/home/user/mysite' # edit
if path not in sys.path:
    sys.path.append(path)

from app import app as application

For Django project, it’s similar to the automitically generated default wsgi.py file but fixing path. The mysiteconfig value should be changed to the project config directory (by default same name as project directory).

import sys
path = '/home/user/mysite' # edit
if path not in sys.path:
    sys.path.append(path)

import os

from django.core.wsgi import get_wsgi_application

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'mysiteconfig.settings') # edit

application = get_wsgi_application()

  • Set virtualenv to /home/user/.virtualenvs/myvenv.

  • Add directories containing static files. For Django projects usual ones are /static/ and /media/ found in /home/user/mysite/static/ and /home/user/mysite/media/ respectively.

  • Reload project and voila! App should now be running.

Of course here it’s assumed that project is otherwise configured correctly. For example in a Django project someone may have to add 'user.pythonanywhere.com' in settings.py’s ALLOWED_HOSTS list.

Trivia: Apparently it was acquired few months ago by Anaconda. There’s also an experimental API that could be used for setting up the app. Thus a paying account can theoretically upload and run an app purely from a local terminal.