Python – Why doesn’t django’s model.save() call full_clean()

djangodjango-modelsdjango-validationpython

I'm just curious if anyone knows if there's good reason why django's orm doesn't call 'full_clean' on a model unless it is being saved as part of a model form.

Note that full_clean() will not be called automatically when you call your model’s save() method. You’ll need to call it manually when you want to run one-step model validation for your own manually created models.
django's full clean doc

(NOTE: quote updated for Django 1.6… previous django docs had a caveat about ModelForms as well.)

Are there good reasons why people wouldn't want this behavior? I'd think if you took the time to add validation to a model, you'd want that validation run every time the model is saved.

I know how to get everything to work properly, I'm just looking for an explanation.

Best Answer

AFAIK, this is because of backwards compatibility. There are also problems with ModelForms with excluded fields, models with default values, pre_save() signals, etc.

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