How can python __new__ method return a string or unicode object instead of class object

Question

How can I create a new string object with Python __new__ method so that the string object should have class attributes also.

For example, I have tested this in Maya:

class A(object):
    def __new__(str, *args, **kwargs):
        return super(A, str).__new__(str)

    def __init__(self, obj):         
        self.obj =str(obj)

    def hai(self):
        print 'hai new obj. you are not string object. you are only cls object'

objA =A('object01')

objA.hai()

Result : 'hai new obj. you are not string object. you are only cls object'

objA

Result : < main .A object at 0x22799710>

I have tested the same with PyNode class of (PyMel)

objB =PyNode('object01')
objB

Result : nt.Transform(u'object01')

But PyNode object is giving a unicode or string object. That means objB can be used directly as string or unicode but objA can't be used like that

How can I get something like objB ouput?

Answer 1

Use

class A(str)

to make A a subclass of str :

class A(str):
    def __new__(cls, *args, **kwargs):
        return super(A, cls).__new__(cls, *args, **kwargs)

    def hai(self):
        print('hai new obj. you are not string object. you are only cls object')

objA =A('object01')

objA.hai()
assert isinstance(objA, str)