Articles tagged with "Django"
Constraints keep the integrity of your system and prevent you from shooting yourself in the foot. Foreign keys are a special type of constraint because, unlike unique, check, and primary keys, they span more than one relation. This makes foreign keys harder to enforce and harder to get right. In this article, I demonstrate common pitfalls, potential optimizations, and implicit behavior related to foreign keys.
Concurrency is not very intuitive - you need to train your brain to consider what happens when multiple processes execute a certain code block at the same time. In this article I present common concurrency challenges and how to overcome them with minimal locking.
A story about how I ended up sending hundreds of users messages saying they got paid when they didn't! In the process we've learned a valuable lesson about nested transactions and Django signals.
Django 3.2 is just around the corner and it's packed with new features. Django versions are usually not that exciting (it's a good thing!), but this time many features were added to the ORM, so I find it especially interesting!
In this article I describe the process we took to identify potential free space, and one surprising find that helped up clear up ~10GB of unused indexed values!
What if mypy could warn you about possible problems at "compile time"? In this article I share a little trick to get mypy to fail when a value in an enumeration type is left unhandled.
If you ever had a test that one day just started to fail, unprovoked, or a test that fails once every blue moon for no apparent reason, it's possible your code is relying on something that is not deterministic. In this article I describe a practical approach to dependency injection in Python that when used correctly, can eliminate nondeterminism and make your code easier to maintain and to test.
In my latest article for RealPython I cover some exotic migration operations, many of the built-in migration CLI commands and demonstrate important migrations concepts such as reversible migrations, migration plans and introspection.
It can be very challenging to test a system that rely heavily on a third party service such as Twilio. In this article, I show how to organize your code in a way that would isolate your bushiness logic and make it easier for you to test it separately.
One of the most challenging aspects of writing good tests is maintaining test fixtures. Good test fixtures motivate developers to write better tests, and bad fixtures can cripple a system to a point where developers fear and avoid them all together. The article covers everything from setting up Pytest for a Django project, creating test fixtures and how to create dependency between fixtures.
