Exception on Custom Lookups when right value is None.

[maherma-adg]

For my current project I need generate a complex queryset filter and I decide implement as custom lookup.

I got the ​example as base to create custom lookup, but during test, this expresion:

data = Rsce.filter(duration__ne = None)

throw an exception. Any other expresion run smoothly.

Looking into code exception are thrown in this piece of code:

if value is None:

if lookups[-1] not in ('exact', 'iexact'):

raise ValueError("Cannot use None as a query value")

IMHO the check in lookups must be avoided on custom lookups, allowing them to manage None values by themselves.