Tastypie API return only one object for given parameters

Question

I am overwriting the get_obj_list function. Following some parameters and a random function I would like to return an object related to the actual object that follows the parameters. This works fine. How can I return only this obj instead of a one-entry-list? Is there another function that better fits my purpose?

class SentenceRandomResource(ModelResource):

    class Meta:
        queryset = Sentence.objects.filter()
        resource_name = 'sentence/random'
        always_return_data = True
        authorization = ReadOnlyAuthorization()
        filtering = {'internal': ALL}

    def obj_get_list(self, bundle, **kwargs):

        if 'case' in bundle.request.GET.keys() and 'lemma' in bundle.request.GET.keys() :
            if 'number'  in bundle.request.GET.keys() :
                words = Word.objects.filter(case = bundle.request.GET['case'], number = bundle.request.GET['number'], lemma = bundle.request.GET['lemma'])
            else :
                words = Word.objects.filter(case = bundle.request.GET['case'], lemma = bundle.request.GET['lemma'])
            number_of_words = len(words)
            if number_of_words > 0 :
                random_index = int(random.random()*number_of_words)+0
                random_word = words[random_index]
                sentence = random_word.sentence

                return [sentence]
            else: ...

        else: ...

Answer 1

Thanks to method prepend_url you may add some special functionality not included in RESTful principles.

import random
from tastypie.http import HttpBadRequest

class SentenceRandomResource(ModelResource):

    class Meta:
        queryset = Sentence.objects.filter()
        resource_name = 'sentence/random'
        always_return_data = True
        authorization = ReadOnlyAuthorization()
        filtering = {'internal': ALL}

    def prepend_urls(self, *args, **kwargs):
        name = 'get_one_random'
        return [url(r"^(?P<resource_name>%s)/%s%s$" %
                    (self._meta.resource_name, name, trailing_slash()),
                    self.wrap_view(name), name="api_%s" % name)]

    def get_one_random(self, request, **kwargs):
        """
        Gets one random sentence of sentences with provided `case` and `lemma` 
        params.
        """
        case = request.GET.get('case')
        lemma = request.GET.get('lemma')
        number = request.GET.get('number')

        if case and lemma:
            query_params = {'case': case, 'lemma': lemma}
            if number is not None:
                query_params['number'] = number
            words = Word.objects.filter(**query_params)

            word = random.choice(words)
            return self.create_response(request, {'sentence': word.sentence.__dict__})

        else:
            return self.error_response(request, {'error': 'lemma and case are required.'},
                                       response_class=HttpBadRequest)

Example use:

GET ..../sentence/random/get_one_random/?case=1&lemma=2

{'sentence': 'asdfasdf'}