Search in multiple django models

search_in_models.py

import operator

from django.db.models.query import QuerySet
from django.utils.encoding import smart_str
from django.db import models

def search_in_models(search_query, model_fields, queryset=False):
    """
    Search in multiple models:
    `model_fields` is are tuples within a tuple defining model_class, search_field pairs
    ((MyModel, ['field1', 'field2', '@field3']),
     (MyOtherModel, ['field2'])
    )
    '@' = case insensitive search
    '^' = case insensitive startswith
    '=' = case insensitive exact
    '' = case insensitive contains (default)
    """
    
    def do_search(model_class, search_query, filter_fields, queryset):
        qs = queryset if queryset else model_class._default_manager.all()
        
        for bit in search_query.split():
            or_queries = [models.Q(**{construct_search(
                smart_str(field_name)): smart_str(bit)})
                    for field_name in filter_fields]
            other_qs = QuerySet(model_class)
            other_qs.dup_select_related(qs)
            other_qs = other_qs.filter(reduce(operator.or_, or_queries))
            #limit results to items wihtin the original qs seeing as the original qs could have been filtered
            qs = qs & other_qs
        return other_qs
    
    def construct_search(field_name):
        # use different lookup methods depending on the notation
        if field_name.startswith('^'):
            return "%s__istartswith" % field_name[1:]
        elif field_name.startswith('='):
            return "%s__iexact" % field_name[1:]
        elif field_name.startswith('@'):
            return "%s__search" % field_name[1:]
        else:
            return "%s__icontains" % field_name
    
    final_search_result = []
    
    for model_field_pair in model_fields:
        qs = do_search(model_field_pair[0], search_query, model_field_pair[1], queryset)
        for qs_item in qs:
            qfinal_search_result.append(qs_item)
    
    return  final_search_result