Simple Django Search

search.py

import re

from django.db.models import Q
from django.shortcuts import render_to_response
from django.template import RequestContext

from apps.missions.models import Mission
from apps.profiles.models import Profile

def normalize_query(query_string,
                    findterms=re.compile(r'"([^"]+)"|(\S+)').findall,
                    normspace=re.compile(r'\s{2,}').sub):
    ''' Splits the query string in invidual keywords, getting rid of unecessary spaces
        and grouping quoted words together.
        Example:
        
        >>> normalize_query('  some random  words "with   quotes  " and   spaces')
        ['some', 'random', 'words', 'with quotes', 'and', 'spaces']
    
    '''
    return [normspace(' ', (t[0] or t[1]).strip()) for t in findterms(query_string)] 



def get_query(query_string, search_fields):
    ''' Returns a query, that is a combination of Q objects. That combination
        aims to search keywords within a model by testing the given search fields.
    '''
    query = None # Query to search for every search term
    terms = normalize_query(query_string)
    for term in terms:
        or_query = None # Query to search for a given term in each field
        for field_name in search_fields:
            q = Q(**{"%s__icontains" % field_name: term})
            if or_query is None:
                or_query = q
            else:
                or_query = or_query | q
        if query is None:
            query = or_query
        else:
            query = query & or_query
    return query



def search(request):
    
    # To get around a weird moderator already registered error.
    from django.db.models import get_model
    Entry = get_model('blog', 'Entry')
    query_string = ''
    results = {}
    params = [{
        'name': 'Blog Post',
        'manager': Entry.objects.published(),
        'fields': ['title', 'body']
    },{
        'name': 'Mission',
        'manager': Mission.objects.published(),
        'fields': ['destination', 'description']
    },{
        'name': 'Profile',
        'manager': Profile.objects.active(),
        'fields': ['occupation', 'bio', 'user__first_name', 'user__last_name']
    }]
    if ('q' in request.GET) and request.GET['q'].strip():
        query_string = request.GET['q']
        for p in params:
            entry_query = get_query(query_string, p['fields'])
            results[p['name']] = p['manager'].filter(entry_query)
    return render_to_response(
        'search/search.html', {
            'query_string': query_string,
            'results': results
        },
        context_instance=RequestContext(request)
    )