Chaining Q objects

[MikeKJ]

Using this as an example from Dan Herrar
enter code here

        from django.db.models import Q
        user_pk = 1
        category_pk = 1  #some times None
        f = Q( user__pk = user_pk, date=now() )
        if category_pk is not None:
            f &= Q( category__pk = category_pk )
        todays_items = Item.objects.filter( f  )

I am constructing a massive filter chain (I'd rather not) so I have...
enter code here

        from django.db.models import Q
        f = Q(availability_text=this)
        if 'cabins' in request.POST:
            cabins = request.POST['cabins']
            if cabins != "0" and cabins != "":
                c = cabins
                c = int(c)
                f &= Q(cabins=c)
            if 'thruster' in request.POST:
                thruster = request.POST['thruster']
                if thruster != 0:
                    t = 1
                    f &= Q(thruster=t)

etc etc

this is the result of an f trial

(AND: ('availability_text', ''), ('bow_thruster', 1))

but I get

"Too many values to unpack" at

                wm = Boat.objects.filter(name=x).filter( f )[:1].get()

which is confusing as I am handling 4 lists and this is the 3rd iteration and it didn't error on iteration 1 or 2

Any insight would be gratefully received

[Matthew Pava]

I’m not entirely sure if the error is from your Q chain, but something I would try is to replace “[:1].get()” with “.first()”.

wm = Boat.objects.filter(name=x).filter( f ).first()

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[Simon Charette]

Hey Mike,

Please provide the full traceback.

Also, since all your conditions are ANDed you could use a dict to build filter() kwargs instead of Q() objects.

Cheers,

Simon

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[MikeKJ]

Cheers Matthew, can't use .first() due to reskinning an existing site with an older version

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[MikeKJ]

many thanks Simon dict filter kwargs was definitely the way to go!