simple is better than complex

There are a few ways to export data to a PDF file using Django. All of them requires a third-party library so to generate the file itself. First I will show how to return a PDF response, which can also be used if you are just serving an existing PDF file. Then I will show how to use ReportLab and WeasyPrint.

Flake8 is a Python library that wraps PyFlakes, pycodestyle and Ned Batchelder’s McCabe script. It is a great toolkit for checking your code base against coding style (PEP8), programming errors (like “library imported but unused” and “Undefined name”) and to check cyclomatic complexity.

This is a very quick tip about how to create a change password view using the built-in PasswordChangeForm.

As part of the Django’s common Web application tools, Django offers a few classes to manage paginated data. You can pass either a list/tuple of objects or an QuerySet. In this tutorial I will show how to paginate data using function based views and how to paginate using class-based views (ListView).

It is a good idea to keep your apps views module small. A common mistake is do much work inside the views functions. For the most part you can create separate modules to do the processing work outside the views and just import it and use the functions inside the views. Another common mistake is a single app implementing many different requirements or serving for many purposes. Sometimes you can split the work into different apps. When it makes sense of course. But sometimes, the views will get big anyway. In this case, you might want to split the views into different files.

In this tutorial you will learn the concepts behind Django file upload and how to handle file upload using model forms. In the end of this post you will find the source code of the examples I used so you can try and explore.

Export data to excel is a common requirement on many web applications. Python makes everything easier. But, nevertheless, it is the kind of task I need to look for references whenever I have to implement.

The Django Signals is a strategy to allow decoupled applications to get notified when certain events occur. Let’s say you want to invalidate a cached page everytime a given model instance is updated, but there are several places in your code base that this model can be updated. You can do that using signals, hooking some pieces of code to be executed everytime this specific model’s save method is trigged.

Since version 1.7, Django counts with the built-in JsonResponse class, which is a subclass of HttpResponse. Its default Content-Type header is set to application/json, which is really convenient. It also comes with a JSON encoder, so you don’t need to serialize the data before returning the response object.

The Django migration system was developed and optmized to work with large number of migrations. Generally you shouldn’t mind to keep a big amount of models migrations in your code base. Even though sometimes it causes some undesired effects, like consuming much time while running the tests. But in scenarios like this you can easily disable the migrations (although there is no built-in option for that at the moment).