Django naming conventions for dates

Question

Is there any naming convention for "created" and "last edit" dates in Django?

ie. in Symfony Framework this fields are named by default:

• created_at
• updated_at

Answer 1

Indeed, as far as I can tell there's no canonical convention for Django, but I really like the Rails convention (which I suppose also inspired Symphony):

• created_at for DateTime fields
• created_on for Date fields

created works fine for creation dates, but as soon as you have more ambiguous fields like activated, it becomes a problem. Is it a boolean or a date/datetime? Naming conventions exist to help developers understand code faster and waste less time with unimportant decisions. That's the philosophy behind the Convention over Configuration paradigm, which is big in the Rails community but not as much in Django's unfortunately. This confusion I mentioned for example is typical and that's why I prefer to always be extra clear:

• If it's a boolean is_activated
• If it's datetime activated_at
• If it's just a date activated_on

I've heard people say that "you shouldn't mix field names with data types" but it seems like a rather empty tip in my opinion and I've never heard any concrete argument behind it. If we want to optimize code readability and decision making then I really think explicit naming conventions are the way to go.

Answer 2

Django Model Utils has a model mixin for this, naming them created and modified -- I recommend using their model mixin to easily standardize across of your models and projects.

Answer 3

I don't think there's something like a canonical way of naming such things in Django. Some parts are well covered by PEP8, mostly because this sort of thing is out of scope of Django, since it's much more a matter of style (and maybe house conventions).

That said, I think it's pretty common to name these fields as created_at and updated_at, and I personally follow this convention when writing my own code. I advise to avoid names like created or updated since they're ambiguous (although some popular libs use that style): are they booleans or something else? is_created/is_updated, if you need those, are better options.

Answer 4

In Django origin models this fields are named based on Model type ie.

• auth.User: date_joined
• comments.Comment: submit_date

So probably we should follow this convention.

Answer 5

I prefer created and updated without the _at suffix. I don't know of any "canonical" preference for naming the fields.

For what it is worth, I think Rails uses created_at / created_on and updated_at / updated_on.