Python collections.abc 模块，ValuesView() 实例源码

def values(self):
        return abc.ValuesView(self)

def test_values(setup_teardown_file):
    """.values provides a value view."""
    f = setup_teardown_file[3]
    grp = f.create_group("test")

    grpa = grp.create_group("a")
    grpb = grp.create_group("b")
    grpc = grp.create_group("c")
    grpd = grp.create_group("d")

    assert isinstance(grp.values(), ValuesView)
    assert list(grp.values()) == [grpa, grpb, grpc, grpd]