Python traitlets 模块，Integer() 实例源码

def AnonymousMapping(**traits):
    """Create an anonymous HasTraits mapping

    This is used when a JSONSchema defines an object inline, rather than in
    a separate statement

    Example
    -------
    >>> Foo = AnonymousMapping(val=T.Integer())
    >>> f = Foo(val=4)
    >>> type(f)
    <class 'traitlets.traitlets.AnonymousMapping'>
    """
    return T.MetaHasTraits('AnonymousMapping', (JSONHasTraits,), traits)

def test_hastraits_defaults():

    class Foo(jst.JSONHasTraits):
        _additional_traits = [T.Integer()]
        name = T.Unicode()

    f = Foo(name="Bob", age=40)
    f.set_trait('year', 2000)
    assert set(f.trait_names()) == {'name', 'age', 'year'}

    with pytest.raises(T.TraitError):
        f.set_trait('foo', 'abc')

    with pytest.raises(T.TraitError):
        f.set_trait('age', 'blah')

def test_AnyOfObject():

    class Foo(jst.JSONHasTraits):
        intval = T.Integer()
        flag = T.Bool()

    class Bar(jst.JSONHasTraits):
        strval = T.Unicode()
        flag = T.Bool()

    class FooBar(jst.AnyOfObject):
        _classes = [Foo, Bar]

    FooBar(strval='hello', flag=True)
    FooBar(intval=5, flag=True)

    with pytest.raises(T.TraitError):
        FooBar(strval=666, flag=False)
    with pytest.raises(T.TraitError):
        FooBar(strval='hello', flag='bad arg')
    with pytest.raises(T.TraitError):
        FooBar(intval='bad arg', flag=False)
    with pytest.raises(T.TraitError):
        FooBar(intval=42, flag='bad arg')

    # Test from_dict
    FooBar.from_dict({'strval': 'hello', 'flag': True})
    FooBar.from_dict({'intval': 42, 'flag': False})