def _load_metadata(self):
        """Load meta data from metadata.xml."""

        assert os.path.exists(self.metadata)

        tree = ET.parse(self.metadata)
        root = tree.getroot()

        for i, tr in enumerate(root.find('mapping')):
            if i == 0:
                _, _, *self.subjects = [td.text for td in tr]
                self.sequence_mappings \
                    = {subject: {} for subject in self.subjects}
            elif i < 33:
                action_id, subaction_id, *prefixes = [td.text for td in tr]
                for subject, prefix in zip(self.subjects, prefixes):
                    self.sequence_mappings[subject][(action_id, subaction_id)]\
                        = prefix

        for i, elem in enumerate(root.find('actionnames')):
            action_id = str(i + 1)
            self.action_names[action_id] = elem.text

        self.camera_ids \
            = [elem.text for elem in root.find('dbcameras/index2id')]

        w0 = root.find('w0')
        self.cameras_raw = [float(num) for num in w0.text[1:-1].split()]
Load meta data from metadata.xml.
mmpose/tools/dataset_converters/preprocess_h36m.py