code: def sort_orbitals(element_pdos):
      
      sorted_orbitals = ['s', 'p', 'py', 'pz', 'px',
                         'd', 'dxy', 'dyz', 'dz2', 'dxz', 'dx2',
                         'f', 'f_3', 'f_2', 'f_1', 'f_0', 'f1', 'f2', 'f3']
      unsorted_keys = element_pdos.keys()
  
      sorted_keys = []
      for key in sorted_orbitals:
          if key in unsorted_keys:
              sorted_keys.append(key)
  
      return sorted_keys
docs: Sort the orbitals of an element's projected density of states.
  
      Sorts the orbitals based on a standard format. E.g. s < p < d.
      Will also sort lm decomposed orbitals. This is useful for plotting/saving.
  
      Args:
          element_pdos (dict): An element's pdos. Should be formatted as a
              :obj:`dict` of ``{orbital: dos}``. Where dos is a
              :obj:`~pymatgen.electronic_structure.dos.Dos` object. For example::
  
                  {'s': dos, 'px': dos}
  
      Returns:
          list: The sorted orbitals.