Query when parameter is none django

Question

I want to make a query, something like

Model.objects.filter(x=x).filter(y=y).filter(z=z) 

... but there are some cases when for example y

Answer 1

A better approach on the otherwise very readable @rolling-stone answer:

models = Model.objects.all()

variables = {'x':x,'y':y,'z':z}

for key, value in variables.items():
    if value is not None:
        models = models.filter(**{key: value})

Anyway, depending on the specific filter, you'll need to apply filters together in the same .filter() call, so the "blind" way only works in the simple cases. See https://docs.djangoproject.com/en/dev/topics/db/queries/#spanning-multi-valued-relationships for more information on those cases.