code: def get_ph_bs_symm_line(bands_path, has_nac=False, labels_dict=None):
      
      return get_ph_bs_symm_line_from_dict(loadfn(bands_path), has_nac,
                                           labels_dict)
docs: Creates a pymatgen PhononBandStructure from a band.yaml file.
      The labels will be extracted from the dictionary, if present.
      If the 'eigenvector'  key is found the eigendisplacements will be
      calculated according to the formula:
      \\exp(2*pi*i*(frac_coords \\dot q) / sqrt(mass) * v
       and added to the object.
  
      Args:
          bands_path: path to the band.yaml file
          has_nac: True if the data have been obtained with the option
              --nac option. Default False.
          labels_dict: dict that links a qpoint in frac coords to a label.