appending a queryset to a list/tuple without evaluating it - django

Question

According to the docs a queryset gets evaluated when list() is called on it.
Is there a way to append a list/tuple with a queryset instead of model objects? Is list() called for every operation on lists/tuples?
e.g:
foo= Foo.objects.all()
bar = Bar.objects.filter(enabled=True)
my_list = []
my_list.append(foo) <-- evaluates
my_list.extend(foo) <-- evaluates
my_tuple = ()
my_tuple = my_tuple + (foo,) <-- evaluates
# so I'm getting
[<Foo: ModelDescription>,<Foo: ModelDescription>,<Bar: ModelDescription>]
#but I want
[<Queryset: Foo>, <Queryset:Bar>]

Answer 1

This is either no longer true or perhaps the way you were checking the type of the elements was inadvertently triggering the evaluation.
To summarize, you can use append() or my_tuple = my_tuple + (foo,). If you try to just print these it will evaluate the QuerySet and output their contents but if you loop through these collections you can work with the actual QuerySet.
>>> a = Author.objects.filter()
>>> b = Book.objects.filter()
>>> type(a), type(b)
(<class 'django.db.models.query.QuerySet'>, <class 'django.db.models.query.QuerySet'>)
>>> l = []
>>> l.append(a)
>>> l.append(b)
>>> type(l[0]), type(l[1])
(<class 'django.db.models.query.QuerySet'>, <class 'django.db.models.query.QuerySet'>)
>>> for q in l:
... print type(q)
...
<class 'django.db.models.query.QuerySet'>
<class 'django.db.models.query.QuerySet'>
>>> my_tuple = ()
>>> my_tuple = my_tuple + (a,)
>>> type(my_tuple[0])
<class 'django.db.models.query.QuerySet'>
>>> len(l)
2
>>> len(my_tuple)
1
>>> print l
[[<Author: Author object>, '...(remaining elements truncated)...'], [<Book: Book object>,]]
>>> len(my_tuple)
1
>>> print my_tuple
([<Author: Author object>, '...(remaining elements truncated)...'],)
>>> len(my_tuple)
1
>>>