code: def get_lattice_type(number):
          
          f = lambda i, j: i <= number <= j
          cs = {'triclinic': (1, 2), 'monoclinic': (3, 15),
                'orthorhombic': (16, 74), 'tetragonal': (75, 142),
                'trigonal': (143, 167), 'hexagonal': (168, 194),
                'cubic': (195, 230)}
  
          crystal_system = None
          for k, v in cs.items():
              if f(*v):
                  crystal_system = k
                  break
  
          if number in [146, 148, 155, 160, 161, 166, 167]:
              return "rhombohedral"
          elif crystal_system == "trigonal":
              return "hexagonal"
          else:
              return crystal_system
docs: Return the lattice crystal system.
  
          Hexagonal cells are differentiated into rhombohedral and hexagonal
          lattices.
  
          Args:
              number (int): The international space group number.
  
          Returns:
              str: The lattice crystal system.