>>> class Test(object):

    def __new__(cls):
        print ("new")
        return super(Test, cls).__new__(cls)

    def __init__(self):
        print ("init")

>>> Test()
new
init

>>> class Test2(object):
    def __str__(self):
        return "I am test 2"

>>> class Test1(object):
    def __new__(cls):
        return Test2()
>>> print(Test1())
I am test 2