def test_simple_subsystem(): lattice = Lattice([8, 8], 2) subsystem = SimpleSubsystem([4, 6], lattice) inside = set() for site in lattice: if site in subsystem: inside.add(site) else: with pytest.raises(ValueError): subsystem.index(site) assert len(inside) == len(subsystem) for i, site in enumerate(subsystem): assert subsystem[i] == site assert subsystem.index(site) == i inside.remove(site) assert len(inside) == 0