Difference between Compress and Clean method in Django Form Fields

Question

I'm writing a custom date field for Credit Card Expiration Fields. I've noticed that in custom field examples, there are two major part that we need to override, clean and compress methods.

I know that we can validate and change return values of the field value in clean method. But what about compress method? Why do we need that and what's the difference in between of clean and compress method?

Answer 1

compress only exists for subclasses of MultiValueField . As the documentation there explains, you use it in place of clean to convert the multiple values (one for each field) into a single value.

For every other type of field, you use clean .