Expand Argument Not Respected When Empty

[davidgolden]

I would expect that when instantiating a serializer and explicitly setting the expand argument, that would be respected no matter what. Instead, the behavior is that if there is an expand query param, that is respected over an empty list argument because empty lists are falsy. Here is the logic in question:

"expand": (
                self._get_permitted_expands_from_query_param(EXPAND_PARAM)
                if not expand
                else []
            ),

Maybe this is the intended behavior but it seems strange to me. Feature or bug?

[KrYpTeD974]

I've just noticed that DjangoRestFramework uses a class empty to handle cases like this.
It might be a lead to solve this issue.

class empty:
    """
    This class is used to represent no data being provided for a given input
    or output value.

    It is required because `None` may be a valid input or output value.
    """
    pass