Why leave explicit null=True when blank is True in IntegerField, DateField etc?

[Paulo Maciel]

It would be better if IntegerField, DateField, etc did not have to leave explicit null=True when blank is True. 

In my opinion it might look like:

class Abc(models.Model):
    number = models.IntegerField(blank=True)  # doesn't need leave explicit null=True, it's should be default if blank is True

What do you think?

[Enrique Paredes]

Well, one can call the Zen of python, about just exactly that. explicit is better than implicit.

In this case, explicit becomes a problem for getting used to it, versus implicit that becomes a strange behavior/bug/wtf when you don't expect it.

I'll rather see a ValueError if this is something the model field can't afford (Doesn't do it already?)

Cheers,

E.

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[Yo-Yo Ma]

Another reason you want the two to be separate is that you might allow a field to be blank in forms but then set the value to some context-specific value (vs a simple default=x) before saving.

[Tom Christie]

That kind of implicit behavior would just leave things more confused.
Writing a few characters less code isn't a benefit if it comes at the expense of making the behavior less obvious.

[Paulo Maciel]

Why confused? It's optional, if the developer wanna put null=True, he could.

I don't think need to be putting null = True, this is redundant. If this is a standard behavior, you need not be explicit.

I think this should be optional, by default these fields should always be null=True implicitly.

Django's philosophy is to simplify.

[Tim Graham]

As Yo-Yo mentioned, there are valid use cases for blank=True, null=False, and I believe having one field option implicitly change another actually adds complexity instead of simplifying things.

[Shai Berger]

Hi,

(edited a little)

On Tuesday 22 September 2015 03:07:37 Tim Graham wrote:
> On Monday, September 21, 2015 at 6:52:08 PM UTC-4, Paulo Maciel wrote:
> > Why confused? It's optional, if the developer wanna put null=True, he
> > could.
> > I don't think need to be putting null = True, this is redundant. If this
> > is a standard behavior, you need not be explicit.
>
> As Yo-Yo mentioned, there are valid use cases for blank=True, null=False,
> and I believe having one field option implicitly change another actually
> adds complexity instead of simplifying things.
>

Even if we did accept some sort of implication there, it would be the other
way around. "null=True" is a feature of the model field itself, while
"blank=True" only sets the default behavior of form fields generated for it. It
would make some sense for null=True to imply blank=True, but not as you
suggest.

Shai.