dehydrate mixin to allow for field selection in Tastypie

dehydrateMixin.py

class fieldSelectMixin(object):
    """
    Mixin to allow field selection, dehydrate method.
    """
    def dehydrate(self, bundle):
        selectedFields = bundle.request.GET.get('fields')

        if selectedFields:
            selectedFields = selectedFields.split(',')
            removedFields = [field for field in bundle.data.keys() if field not in selectedFields]

            for field in removedFields:
                del bundle.data[field]

        return bundle