from django_filters import BaseInFilter,NumberFilter

class NumberInFilter(BaseInFilter, NumberFilter):
    pass

class OrderFilter(django_filters.FilterSet):
    code = django_filters.CharFilter(field_name='code', lookup_expr='icontains')
    status = NumberInFilter(field_name='status',lookup_expr='in')
    type = NumberInFilter(field_name='type',lookup_expr='in')
    start_time = django_filters.DateTimeFilter(field_name='create_time',lookup_expr='gte',help_text = '%Y-%m-%d %H:%M:%S')
    end_time = django_filters.DateTimeFilter(field_name='create_time',lookup_expr='lt')
    name = django_filters.CharFilter(field_name='name',lookup_expr='icontains')
    pu_id= django_filters.NumberFilter(field_name='pu_id',lookup_expr='exact')
    l_id= django_filters.NumberFilter(field_name='l_id',lookup_expr='exact')
    l_name = django_filters.CharFilter(field_name='l_id',method='get_l_id')
    pt_name = django_filters.CharFilter(field_name='pu_id',method='get_pt_name')

    def get_pt_name(self,queryset,name,value):
        pu_id = list(User.objects.filter(pt_name__icontains=value).values_list('id',flat=True))
        return queryset.filter(pu_id__in=pu_id)

    def get_l_id(self,queryset,name,value):
        l_id = list(Location.objects.filter(l_name__icontains=value).values_list('id',flat=True))
        return queryset.filter(l_id__in=l_id)

    class Meta:
        model = Order
        fields = ['code','status','type','start_time','end_time','name','pu_id','l_id','l_name','pt_name']

https://django-filter.readthedocs.io/en/stable/ref/filters.html?highlight=BaseInFilter#baseinfilter