How to use the sidekit.bosaris.key.Key function in SIDEKIT

def read_txt(input_file_name):
        """Creates a Key object from information stored in a text file.

            :param input_file_name: name of the file to read from
        """
        key = Key()

        models, testsegs, trial = numpy.loadtxt(input_file_name,
                                                delimiter=' ',
                                                dtype={'names': ('mod', 'seg', 'key'),
                                                       'formats': ('S1000', 'S1000', 'S10')},
                                                unpack=True)

        models = models.astype('|O', copy=False).astype('S', copy=False)
        testsegs = testsegs.astype('|O', copy=False).astype('S', copy=False)
        trial = trial.astype('|O', copy=False).astype('S', copy=False)

        if sys.version_info[0] == 3:
            models = models.astype('U', copy=False)
            testsegs = testsegs.astype('U', copy=False)
            trial = trial.astype('U', copy=False)

def read(input_file_fame):
        """Reads a Key object from an hdf5 file.
  
        :param input_file_fame: name of the file to read from
        """
        with h5py.File(input_file_fame, "r") as f:

            key = Key()
            key.modelset = f.get("modelset").value
            key.segset = f.get("segset").value

            # if running python 3, need a conversion to unicode
            if sys.version_info[0] == 3:
                key.modelset = key.modelset.astype('U100', copy=False)
                key.segset = key.segset.astype('U100', copy=False)

            trialmask = f.get("trial_mask").value
            key.tar = (trialmask == 1)
            key.non = (trialmask == -1)

            assert key.validate(), "Error: wrong Key format"
            return key

:param keep: a boolean indicating whether modlist and seglist are the
            models to keep or discard.

        :return: a filtered version of 'inkey'.
        """
        if keep:
            keepmods = modlist
            keepsegs = seglist
        else:
            keepmods = diff(self.modelset, modlist)
            keepsegs = diff(self.segset, seglist)

        keepmodidx = numpy.array(ismember(self.modelset, keepmods))
        keepsegidx = numpy.array(ismember(self.segset, keepsegs))

        outkey = Key()
        outkey.modelset = self.modelset[keepmodidx]
        outkey.segset = self.segset[keepsegidx]
        tmp = self.tar[numpy.array(keepmodidx), :]
        outkey.tar = tmp[:, numpy.array(keepsegidx)]
        tmp = self.non[numpy.array(keepmodidx), :]
        outkey.non = tmp[:, numpy.array(keepsegidx)]

        assert(outkey.validate())

        if self.modelset.shape[0] > outkey.modelset.shape[0]:
            logging.info('Number of models reduced from %d to %d', self.modelset.shape[0], outkey.modelset.shape[0])
        if self.segset.shape[0] > outkey.segset.shape[0]:
            logging.info('Number of test segments reduced from %d to %d', self.segset.shape[0], outkey.segset.shape[0])
        return outkey

Key objects to merge in the curent one.

        :param key_list: the list of Keys to merge
        """
        # the output key must have all models and segment in the input
        # keys (only once) and the same target and non-target trials.
        # It is an error if a trial is a target in one key and a
        # non-target in another, but a target or non-target marker will
        # override a 'non-trial' marker.
        assert isinstance(key_list, list), "Input is not a list"
        for key in key_list:
            assert isinstance(key_list, list), \
                    '{} {} {}'.format("Element ", key, " is not a list")

        for key2 in key_list:
            key_new = Key()
            key1 = self

            # create new ndx with empty masks
            key_new.modelset = numpy.union1d(key1.modelset, key2.modelset)
            key_new.segset = numpy.union1d(key1.segset, key2.segset)

            # expand ndx1 mask
            tar_1 = numpy.zeros((key_new.modelset.shape[0],
                                key_new.segset.shape[0]),
                                dtype="bool")
            non_1 = numpy.zeros((key_new.modelset.shape[0],
                                key_new.segset.shape[0]), dtype="bool")
            model_index_a = numpy.argwhere(numpy.in1d(key_new.modelset, key1.modelset))
            model_index_b = numpy.argwhere(numpy.in1d(key1.modelset, key_new.modelset))
            seg_index_a = numpy.argwhere(numpy.in1d(key_new.segset, key1.segset))
            seg_index_b = numpy.argwhere(numpy.in1d(key1.segset, key_new.segset))