Exhaustiveness Checking with Mypy
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.
Python
Articles tagged with "Python"
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Stop Using datetime.now!
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.
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How to Move a Django Model to Another App
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.
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Testing an Interactive Voice Response System With Python and Pytest
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.
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How to Provide Test Fixtures for Django Models in Pytest
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.
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Using Markdown in Django
How we developed a Markdown extension to manage content in Django sites.
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Building an IVR System with Python, Django and Twilio
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.
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How "Export to Excel" Almost Killed Our System
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.
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Fastest Way to Load Data Into PostgreSQL Using Python
Explore the best way to import messy data from remote source into PostgreSQL using Python and Psycopg2. The data is big, fetched from a remote source, and needs to be cleaned and transformed.
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Improve Serialization Performance in Django Rest Framework
When a developer chooses Python, Django, or Django Rest Framework, it's usually not because of its blazing fast performance. All of this doesn't mean performance is not important. As this story taught us, major performance boosts can be gained with just a little attention, and a few small changes.
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