def iter_items(self, path, alt=PRIMARY_ALT):
        fn_base = self.to_fs_path(path)

        if alt is None:
            alts = self.config.list_alternatives()
            single_alt = False
        else:
            alts = [alt]
            single_alt = True

        choiceiter = _iter_filename_choices(fn_base, alts, self.config)

        for fs_path, actual_alt, is_attachment in choiceiter:
            if not os.path.isfile(fs_path):
                continue

            # This path is actually for an attachment, which means that we
            # cannot have any items below it and will just abort with an
            # empty iterator.
            if is_attachment:
                break

            try:
                dir_path = os.path.dirname(fs_path)
                for filename in os.listdir(dir_path):
                    if not isinstance(filename, text_type):
                        try:
                            filename = filename.decode(fs_enc)
                        except UnicodeError:
                            continue

                    if filename.endswith('.lr') or \
                       self.env.is_uninteresting_source_name(filename):
                        continue

                    # We found an attachment.  Attachments always live
                    # below the primary alt, so we report it as such.
                    if os.path.isfile(os.path.join(dir_path, filename)):
                        yield filename, PRIMARY_ALT, True

                    # We found a directory, let's make sure it contains a
                    # contents.lr file (or a contents+alt.lr file).
                    else:
                        for content_alt in _iter_content_files(
                                os.path.join(dir_path, filename), alts):
                            yield filename, content_alt, False
                            # If we want a single alt, we break here so
                            # that we only produce a single result.
                            # Otherwise this would also return the primary
                            # fallback here.
                            if single_alt:
                                break
            except IOError as e:
                if e.errno != errno.ENOENT:
                    raise
                continue

            # If we reach this point, we found our parent, so we can stop
            # searching for more at this point.
            break
Iterates over all items below a path and yields them as
dataset/ETHPy150Open lektor/lektor/lektor/db.py/Database.iter_items