def load_metadata_from_desc_file(self, desc_file, partition='train',
                                     max_duration=10.0,):
        """ Read metadata from the description file
            (possibly takes long, depending on the filesize)
        Params:
            desc_file (str):  Path to a JSON-line file that contains labels and
                paths to the audio files
            partition (str): One of 'train', 'validation' or 'test'
            max_duration (float): In seconds, the maximum duration of
                utterances to train or test on
        """
        logger.info('Reading description file: {} for partition: {}'
                    .format(desc_file, partition))
        audio_paths, durations, texts = [], [], []
        with open(desc_file) as json_line_file:
            for line_num, json_line in enumerate(json_line_file):
                try:
                    spec = json.loads(json_line)
                    if float(spec['duration']) > max_duration:
                        continue
                    audio_paths.append(spec['key'])
                    durations.append(float(spec['duration']))
                    texts.append(spec['text'])
                except Exception as e:
                    # Change to (KeyError, ValueError) or
                    # (KeyError,json.decoder.JSONDecodeError), depending on
                    # json module version
                    logger.warn('Error reading line #{}: {}'
                                .format(line_num, json_line))
                    logger.warn(str(e))

        if partition == 'train':
            self.train_audio_paths = audio_paths
            self.train_durations = durations
            self.train_texts = texts
        elif partition == 'validation':
            self.val_audio_paths = audio_paths
            self.val_durations = durations
            self.val_texts = texts
        elif partition == 'test':
            self.test_audio_paths = audio_paths
            self.test_durations = durations
            self.test_texts = texts
        else:
            raise Exception("Invalid partition to load metadata. "
                            "Must be train/validation/test")
 Read metadata from the description file
            (possibly takes long, depending on the filesize)
        Params:
            desc_file (str):  Path to a JSON-line file that contains labels and
                paths to the audio files
            partition (str): One of 'train', 'validation' or 'test'
            max_duration (float): In seconds, the maximum duration of
                utterances to train or test on
        
data_generator.py