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.
How we developed a Markdown extension to manage content in Django sites.
Last year my team and I worked on a very challenging IVR system. After almost a year in production and thousands of processed transactions, I teamed up with the great people over at the Twilio blog to write an introductory tutorial for developing IVR systems using Django and Twilio IVR.
Understand GROUP BY in Django ORM by comparing QuerySets and SQL side by side. If SQL is where you are most comfortable, this is the Django GROUP BY tutorial for you.
SQL is used by analysts, data scientists, product managers, designers and many others. These professionals have access to databases, but they don't always have the intuition and understanding to write efficient queries. In an effort to make my team write better SQL, I went over reports written by non-developers and code reviews, and gathered common mistakes and missed optimization opportunities in SQL.
SQL injection attacks are constantly ranked among the most common attacks against systems. While binding values is very common, I often find my self needing to being table and column names as well. This article will walk you through everything you need to know about SQL injections in Python.
Inspired by an actual incident we had in one of our systems caused by an "Export to Excel" functionality implemented in Python, we go through the process of identifying the problem, experimenting and benchmarking different solutions.
