title: Django rest framework filter numbers less than list
body: <p>I am using DRF and package Django-Filter version 1.1.</p>
  
  <p>In get call I am passing more than one values like 10,20,30, 40 in query parameter as below,</p>
  
  <p><a href="http://websiteapi.comp/searchFilter?persona=name&amp;age=10,20,30" rel="nofollow noreferrer">http://websiteapi.comp/searchFilter?persona=name&amp;age=10,20,30</a></p>
  
  <p>so based on the value sent in <strong>age</strong> parameter, in this case 10,20,30, I want get all the records which are <strong>less than</strong> 10,20,30 values.</p>
  
  <p>Below is the my code snippet</p>
  
  <pre><code>class ListFilter(Filter):
    def filter(self, qs, value):
      value_list = value.split(u',')
      return super(ListFilter, self).filter(qs, Lookup(value_list, 'in'))
  
  class SqureFeetFilter(Filter):
      def filter(self, qs, value):
          value_list = value.split(u',')
          return super(SqureFeetFilter, self).filter(qs, Lookup(value_list, 'range'))
  
  class ProfileFiltter(django_filters.FilterSet):
      person = ListFilter(name='person')
      sf = SqureFeetFilter(name='age',lookup_expr='range')
  
      class Meta:
          model = Profile
          fields =  [ 'person','age']
  
  class ProfileSearchVieset(viewsets.ModelViewSet):
          queryset = Profile.objects.all()
          serializer_class = ProfileSerializer
          permission_classes = [IsAuthenticated]
          filter_backends = (DjangoFilterBackend,)
          filter_class =ProfileFiltter
  </code></pre>
  
  <p>Current by using range look_up expression I am able to get value between two number, but when there are more than 2 values, not able to get less than value between passed number.</p>
  
  <p><strong>example</strong>: if I pass <strong>?age=10,20,30</strong>, then result can be like this 10,12,13,17,19,10,23,22,25,29,30. </p>
  
  <p>Please guide me</p>
  
  <p>Thanks all</p>