code: def _get_forces(self, vasprun_etree):
          
          forces = []
          for event, element in vasprun_etree:
              if element.attrib['name'] == 'forces':
                  for v in element:
                      forces.append([float(x) for x in v.text.split()])
          return np.array(forces)
docs: vasprun_etree = etree.iterparse(fileptr, tag='varray')