Now I have upgraded to Python-3, porting my site to Django 2.0 was pretty straightforward.
Part 4 of the Running to Stand Still series.
Upgrading
The Django website has recommendations for how to upgrade which boil down to
- Do it one release at a time (1.9 → 1.10 → 1.11 → 2.0)
- Use the latest point release of each minor release.
- Make liberal use of the
-Walloption topythonto check for deprecated features.
At first I used commands like
python -Wall ./manage.py test
to check for deprecated features, such as the change from the
MIDDLEWARE_CLASSES setting to MIDDLEWARE, fixed these, and repeated.
I am using Pip-tools to maintain my requirements.txt file. To upgrade to the
latest Django 1.10.x one way is to update requirements.in to have like
django<1.11 and run commands like the following:
pip-compile --upgrade requirements.in
pip install -r requirements.txt
If you are using Pipenv instead then you will do something similar but probably with a single much more stylish command.
And then repeat the testing cycle.
Main Gotcha
With the benefit of hindsight it would have been better if my test cycle had included running the server:
python -Wall ./manage.py runserver 8001
There were some template changes that did get covered by the tests but caused a deprecation warning when rendering a page for real.
Lessons
This went smoother than previous upgrades, partly I guess because Django is converging on perfection and partly because the deprecation mechanism built in to recent Python verisons makes it easier for them to guide me though the process. (Also this is not a very complicated site.)