Member-only story
5 Ways to get Enums in Python
There should be one — and preferably only one — obvious way to do it.
An Enum is a collection of static values, typically strings or integers. They are used pretty often — or at least they should be. At Cashlink, we typically use them to track steps for longer processes.
Enums are a way to group constants. Constants are useful to prevent typos as your editor can warn you when a value is not part of an enum, but it cannot warn you that a string or an integer is invalid. Grouping constants in Enums gives you a couple of advantages.
Before we dive into it, let’s look at some applications for enums.
Examples of Enums
- Statuses: You’re writing a backend and you want to return a status code, this should be an enum. Instead of writing
return 404you writereturn status.HTTP_404_NOT_FOUND. In general, variables that contain a finite set of statuses should probably have an Enum as value. Look for “state” or “status”. - Choices: It might be salutations a user can choose from or roles of users. Countries of origin, timezones, …. Look for “choice” or sometimes just lists within your code.
- Types: You could have different types of users, subscriptions, products, …
- Steps: If you track the user funnel you might have a constant for each step. Depending on that you could have different behavior. The set of all steps could be an Enum.
- Flags: The Unix permission system which represents Read / Write / Execute as binary flags in a 3-bit sequence is another example of what you would want to do with an Enum.
What you want to do with enums
Get editor support
You can always just use a constant. But when you use an editor, you typically want to get auto-completion by your editor.
Nice representation when printing
There should be a good way to convert it to a string. For example, when you print the HTTP status code I think NOT_FOUND is way better than 404.
