Django June 2023: Tips & Discussions

Django is definitely not the only thing I use Python for, but I use and teach Django quite often. In the first half of 2023, I held 3 Django-related trainings, did some Django consulting, and I worked on the Python Morsels web app, which is written in Django.

My Django students and clients often ask questions that make me realize I have Django opinion that might be of interest to someone else (a fact that's challenging to recognize in isolation)! So for the month of June I decided to post daily-ish social media threads (to both Mastodon and Twitter) on interesting Django-related ideas using the tag #DjangoJune.

Here's a summary of the couple dozen Django tips from this #DjangoJune adventure, including links to the Mastodon threads and occasional links to the Twitter threads (when discussion on Twitter was sufficiently different).

Learning and community

• Some thoughts on Django Learning: typically I recommend using the Django Girls tutorial followed by the official tutorial
• The most important Django resources I can recommend: djangopackages.org and awesomedjango.org

Architecture and code style

• On naming Django apps: pluralize the primary model or use a "topic" noun (Twitter thread also)
• When to make a new Django app: making a new app versus reusing an existing one
• Class-based views or function-based views?: there's not an easy answer, but I linked some resources to consider (Tweet reply for CBVs)
• Should you use Django signals on your own models?: I recommend against them

Admin-specific tips

• Move your admin site's URL: /admin/ is often visited by bots trying to break into Django admin sites
• Link the admin in your nav bar (but only make it visible to admin users)
• Speed up the admin interface: list_select_related, raw_id_fields, annotations
• Third-party libraries for enhancing the admin site: django-admin-sortable, django-admin-rangefilter, django-relatives, and more

SQL query debugging

• How can you see the SQL queries you've run? (django.db.connection.queries)
• What's the SQL that Django will generate from this QuerySet? (convert the query attribute to a string)
• Avoiding one query ballooning into many: use select_related and prefetch_related
• Seasoned Django devs need to know their ORM: includes recommended DjangoCon talks comparing SQL to the ORM
• Embrace the laziness of the Django ORM

Where do I write my code?

No, you don't need to completely avoid business logic in your models module. In fact I recommend that you:

• Use properties on models: use these for "derived" data that's related to a particular model
• Use QuerySet methods: use these to reduce repetition between your Django queries
• Add methods to your models as needed: yes, this is okay! (if the method actually makes sense on the model)

But isn't dumping lots of logic in models unwieldy? What about service layers?

• Most Django devs avoid service layers. Why? Because this often involves re-implementing parts of Django. Also see the Twitter thread that included a sub-thread with some long-time Django users whose advice I'd heed (Jeff, Frank, and Simon)
• Where should your code go? There's not a simple answer, but I do have some guidelines I tend to follow.
• Refactoring a Django model with too much code in it: I often use composition with cached properties

Miscellaneous musings

• Embrace the get_absolute_url method: both to enhance the admin interface and to make URL lookups easier in your templates and views
• Running Django code in the background: use Celery or another queuing system (Twitter thread also)
• I recommend django-simple-history: I use django-simple-history in pretty much all of my projects
• You can assign F objects directly to model attributes: this can help avoid race conditions on database saves
• Your favorite Django libraries: I asked this on Mastodon and on Twitter
• I asked what Django idiom you wish you'd known sooner and what Django feature seems underused on Twitter as well as on Mastodon

Tim Schilling also shared a new explainer on Django migrations earlier this month using the Django June hashtag.

Keep in touch

I rarely focus so heavily on publicly teaching Django; my usual focus is teaching core Python skills.

If you'd like to follow my Python musings, I recommend subscribing to my weekly tips. I send one share 3-paragraph-ish Python tip every Wednesday morning to my mailing list. If you don't do emails, you can find me sharing Python ponderings on YouTube, Mastodon, Twitter, and LinkedIn.

If you're interested in deepening your Python skills in a very hands-on way, try Python Morsels.