There's a Package for That

A Django Lightning Talk

There's a
Package
for That.

awesomedjango.org

Use case #01

Your client asks:
"Who changed that record,
and when?"

You have no audit trail.
You have no idea.

Use case #01

There's a
package
for that.

Use case #01

django-simple-history

Stores a full change history for every model instance.
View diffs, revert changes — straight from the Django admin.

pip install django-simple-history

github.com/django-commons/
django-simple-history

Use case #02

You want to run logic
when a model field changes —
but only if the old value
was something specific.

You reach for
another Signal handler.

Use case #02

There's a
package
for that.

Use case #02

django-lifecycle

Declarative model lifecycle hooks. No more post_save spaghetti.
@hook(AFTER_UPDATE, when="status", has_changed=True)
Logic lives on the model. Readable. Testable. Done.

pip install django-lifecycle

github.com/rsinger86/
django-lifecycle

Use case #03

You need background tasks.

Someone says: "Just use Celery."

Now you maintain Redis,
a broker, a worker, Flower, Beat —
to send a welcome email.

Use case #03

There's a
package
for that.

Use case #03

django-tasks

The official Django background task backport, based on DEP 14.
DB-backed. No broker. No extra infrastructure.
@task() def send_welcome(user_id): ... — that's it.

pip install django-tasks

github.com/realOrangeOne/
django-tasks

Use case #04

Production is on fire.
You grep the logs.

Every request's log lines
are mixed together.

You can't tell which line
belongs to which request.

Use case #04

There's a
package
for that.

Use case #04

django-guid

Middleware that injects a unique Correlation-ID into every log message
for the duration of a request — automatically.
Also forwards the ID to downstream services.

pip install django-guid

github.com/snok/
django-guid

Use case #05

You want to catch N+1 queries —
not in the browser devbar,

but in CI,
before they ever hit prod.

Use case #05

There's a
package
for that.

Use case #05

django-zeal

Detects N+1 queries and raises clear, human-readable errors
during your test suite. Fails in CI. Ships nothing.
Massively underrated.

pip install django-zeal

github.com/taobojlen/
django-zeal

Use case #06

New feature is ready.
Roll it out to 10% of users first.

Without a redeploy.
Without an if/else jungle.

Use case #06

There's a
package
for that.

Use case #06

django-waffle

Feature flags, switches, and percentage-based samples.
Managed live via the Django admin. No redeploy needed.
Roll out to groups, users, or a random sample.

pip install django-waffle

github.com/django-waffle/
django-waffle

Use case #07

You need testable,
structured transactional emails.

Not send_mail("Subject", ...)
copy-pasted across the codebase.

Actual unit-testable email objects.

Use case #07

There's a
package
for that.

Use case #07

django-pony-express

Class-based emails — each email is a proper Python class.
Built-in test suite: assert email content without sending.
Clean, structured, no magic strings scattered everywhere.

pip install django-pony-express

github.com/ambient-innovation/
django-pony-express

Special case

You want Django to automatically detect
when a teammate pushes a commit
without tests,
cross-reference their Slack calendar,
wait until they're in a meeting,
then send a
passive-aggressive DM.

There's a package
for that.

Nope.

There is no package for that.

Special case

Some problems
aren't technical.

This is a team problem.
Or a hiring problem.
Or a leadership problem.

No package in the world helps you here.

What does help: pytest + required coverage in CI.
Block the merge before it happens.
That package is called: consistency.

Go explore.
There's a package
for (almost) everything.

Full list → awesomedjango.org
These slides → christoph-teichmeister.github.io/theres-a-package-for-that