Flask Framework Cookbook

Creating custom 404 and 500 handlers

Every application throws errors to users at some point of time. These errors can be due to the user typing a wrong URL (404), application overload (500), or something forbidden for a certain user to access (403). A good application handles these errors in an interactive way instead of showing an ugly white page, which makes no sense to most users. Flask provides an easy-to-use decorator to handle these errors.

Getting ready

The Flask app object has a method called errorhandler(), which enables us to handle our application's errors in a much more beautiful and efficient manner.

How to do it…

Consider the following code snippet:

@app.errorhandler(404) def page_not_found(e): return render_template('404.html'), 404 ...