def tables_used_by_fixtures(fixture_labels, using=DEFAULT_DB_ALIAS):
    """Act like Django's stock loaddata command, but, instead of loading data,
    return an iterable of the names of the tables into which data would be
    loaded."""
    # Keep a count of the installed objects and fixtures
    fixture_count = 0
    loaded_object_count = 0
    fixture_object_count = 0
    tables = set()

    class SingleZipReader(zipfile.ZipFile):
        def __init__(self, *args, **kwargs):
            zipfile.ZipFile.__init__(self, *args, **kwargs)
            if settings.DEBUG:
                assert len(self.namelist()) == 1, "Zip-compressed fixtures must contain only one file."
        def read(self):
            return zipfile.ZipFile.read(self, self.namelist()[0])

    compression_types = {
        None:   file,
        'gz':   gzip.GzipFile,
        'zip':  SingleZipReader
    }
    if has_bz2:
        compression_types['bz2'] = bz2.BZ2File

    app_module_paths = []
    for app in get_apps():
        if hasattr(app, '__path__'):
            # It's a 'models/' subpackage
            for path in app.__path__:
                app_module_paths.append(path)
        else:
            # It's a models.py module
            app_module_paths.append(app.__file__)

    app_fixtures = [os.path.join(os.path.dirname(path), 'fixtures') for path in app_module_paths]
    for fixture_label in fixture_labels:
        parts = fixture_label.split('.')

        if len(parts) > 1 and parts[-1] in compression_types:
            compression_formats = [parts[-1]]
            parts = parts[:-1]
        else:
            compression_formats = list(compression_types.keys())

        if len(parts) == 1:
            fixture_name = parts[0]
            formats = serializers.get_public_serializer_formats()
        else:
            fixture_name, format = '.'.join(parts[:-1]), parts[-1]
            if format in serializers.get_public_serializer_formats():
                formats = [format]
            else:
                formats = []

        if not formats:
            # stderr.write(style.ERROR("Problem installing fixture '%s': %s is
            # not a known serialization format.\n" % (fixture_name, format)))
            return set()

        if os.path.isabs(fixture_name):
            fixture_dirs = [fixture_name]
        else:
            fixture_dirs = app_fixtures + list(settings.FIXTURE_DIRS) + ['']

        for fixture_dir in fixture_dirs:
            # stdout.write("Checking %s for fixtures...\n" %
            # humanize(fixture_dir))

            label_found = False
            for combo in product([using, None], formats, compression_formats):
                database, format, compression_format = combo
                file_name = '.'.join(
                    p for p in [
                        fixture_name, database, format, compression_format
                    ]
                    if p
                )

                # stdout.write("Trying %s for %s fixture '%s'...\n" % \
                # (humanize(fixture_dir), file_name, fixture_name))
                full_path = os.path.join(fixture_dir, file_name)
                open_method = compression_types[compression_format]
                try:
                    fixture = open_method(full_path, 'r')
                    if label_found:
                        fixture.close()
                        # stderr.write(style.ERROR("Multiple fixtures named
                        # '%s' in %s. Aborting.\n" % (fixture_name,
                        # humanize(fixture_dir))))
                        return set()
                    else:
                        fixture_count += 1
                        objects_in_fixture = 0
                        loaded_objects_in_fixture = 0
                        # stdout.write("Installing %s fixture '%s' from %s.\n"
                        # % (format, fixture_name, humanize(fixture_dir)))
                        try:
                            objects = serializers.deserialize(format, fixture, using=using)
                            for obj in objects:
                                objects_in_fixture += 1
                                if router.allow_syncdb(using, obj.object.__class__):
                                    loaded_objects_in_fixture += 1
                                    tables.add(
                                        obj.object.__class__._meta.db_table)
                            loaded_object_count += loaded_objects_in_fixture
                            fixture_object_count += objects_in_fixture
                            label_found = True
                        except (SystemExit, KeyboardInterrupt):
                            raise
                        except Exception:
                            fixture.close()
                            # stderr.write( style.ERROR("Problem installing
                            # fixture '%s': %s\n" % (full_path, ''.join(tra
                            # ceback.format_exception(sys.exc_type,
                            # sys.exc_value, sys.exc_traceback)))))
                            return set()
                        fixture.close()

                        # If the fixture we loaded contains 0 objects, assume that an
                        # error was encountered during fixture loading.
                        if objects_in_fixture == 0:
                            # stderr.write( style.ERROR("No fixture data found
                            # for '%s'. (File format may be invalid.)\n" %
                            # (fixture_name)))
                            return set()

                except Exception:
                    # stdout.write("No %s fixture '%s' in %s.\n" % \ (format,
                    # fixture_name, humanize(fixture_dir)))
                    pass

    return tables
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/django-nose-1.3/django_nose/fixture_tables.py/tables_used_by_fixtures/original