def setUpTestData(cls):
        batch_num = 0
        section_num = 0
        voter_num = 0
        party_num = 0
        position_num = 0
        candidate_num = 0
        num_elections = 2
        voters = list()
        positions = dict()
        for i in range(num_elections):
            election = Election.objects.create(name='Election {}'.format(i))
            positions[str(election.name)] = list()

            num_batches = 2
            for j in range(num_batches):
                batch = Batch.objects.create(year=batch_num, election=election)
                batch_num += 1

                num_sections = 2 if j == 0 else 1
                for k in range(num_sections):
                    section = Section.objects.create(
                        section_name=str(section_num)
                    )
                    section_num += 1

                    num_students = 2
                    for l in range(num_students):
                        voter = User.objects.create(
                            username='user{}'.format(voter_num),
                            first_name=str(voter_num),
                            last_name=str(voter_num),
                            type=UserType.VOTER
                        )
                        voter.set_password('voter')
                        voter.save()
                        voter_num += 1

                        VoterProfile.objects.create(
                            user=voter,
                            batch=batch,
                            section=section
                        )

                        voters.append(voter)

            num_positions = 3
            for i in range(num_positions):
                position = CandidatePosition.objects.create(
                    position_name='Position {}'.format(position_num),
                    election=election
                )

                positions[str(election.name)].append(position)

                position_num += 1

            num_parties = 3
            for j in range(num_parties):
                party = CandidateParty.objects.create(
                    party_name='Party {}'.format(party_num),
                    election=election
                )
                party_num += 1

                if j != 2:  # Let every third party have no candidates.
                    num_positions = 3
                    for k in range(num_positions):
                        position = positions[str(election.name)][k]

                        candidate = Candidate.objects.create(
                            user=voters[candidate_num],
                            party=party,
                            position=position,
                            election=election
                        )

                        Vote.objects.create(
                            user=voters[candidate_num],
                            candidate=candidate,
                            election=election
                        )

                        candidate_num += 1

        # Let's give one candidate an additional vote to really make sure that
        # we all got the correct number of votes.
        Vote.objects.create(
            user=voters[0],
            # NOTE: The voter in voter[1] is a Position 1 candidate of
            #       Party 1, where the voter in voter[0] is a member.
            candidate=Candidate.objects.get(user=voters[1]),
            election=Election.objects.get(name='Election 0')
        )

        _admin = User.objects.create(username='admin', type=UserType.ADMIN)
        _admin.set_password('root')
        _admin.save()
def find_many_example_files(
        top_directory_name, shuffled=True, first_spc_date_string=None,
        last_spc_date_string=None, first_batch_number=None,
        last_batch_number=None, raise_error_if_any_missing=True):
    """Looks for many files with input examples.

    :param top_directory_name: See doc for `find_example_file`.
    :param shuffled: Same.
    :param first_spc_date_string: [used only if `shuffled = False`]
        First SPC date (format "yyyymmdd").  This method will look for all SPC
        dates from `first_spc_date_string`...`last_spc_date_string`.
    :param last_spc_date_string: See above.
    :param first_batch_number: [used only if `shuffled = True`]
        First batch number (integer).  This method will look for all batches
        from `first_batch_number`...`last_batch_number`.
    :param last_batch_number: See above.
    :param raise_error_if_any_missing: Boolean flag.  If *any* desired file is
        not found and `raise_error_if_any_missing = True`, this method will
        error out.
    :return: example_file_names: 1-D list of paths to example files.
    :raises: ValueError: if no files are found.
    """

    error_checking.assert_is_boolean(shuffled)

    if shuffled:
        error_checking.assert_is_integer(first_batch_number)
        error_checking.assert_is_integer(last_batch_number)
        error_checking.assert_is_geq(first_batch_number, 0)
        error_checking.assert_is_geq(last_batch_number, first_batch_number)

        example_file_pattern = (
            '{0:s}/batches{1:s}-{1:s}/input_examples_batch{1:s}.nc'
        ).format(top_directory_name, BATCH_NUMBER_REGEX)

        example_file_names = glob.glob(example_file_pattern)

        if len(example_file_names) > 0:
            batch_numbers = numpy.array(
                [_file_name_to_batch_number(f) for f in example_file_names],
                dtype=int)
            good_indices = numpy.where(numpy.logical_and(
                batch_numbers >= first_batch_number,
                batch_numbers <= last_batch_number
            ))[0]

            example_file_names = [example_file_names[k] for k in good_indices]

        if len(example_file_names) == 0:
            error_string = (
                'Cannot find any files with batch number from {0:d}...{1:d}.'
            ).format(first_batch_number, last_batch_number)
            raise ValueError(error_string)

        return example_file_names

    spc_date_strings = time_conversion.get_spc_dates_in_range(
        first_spc_date_string=first_spc_date_string,
        last_spc_date_string=last_spc_date_string)

    example_file_names = []
    for this_spc_date_string in spc_date_strings:
        this_file_name = find_example_file(
            top_directory_name=top_directory_name, shuffled=False,
            spc_date_string=this_spc_date_string,
            raise_error_if_missing=raise_error_if_any_missing)

        if not os.path.isfile(this_file_name):
            continue
        example_file_names.append(this_file_name)

    if len(example_file_names) == 0:
        error_string = (
            'Cannot find any file with SPC date from {0:s} to {1:s}.'
        ).format(first_spc_date_string, last_spc_date_string)

        raise ValueError(error_string)

    return example_file_names