No idea what's your actual use case is, but you can do something like this using a descriptor:

class Desc(object):
    
    def __get__(self, ins, typ):
        if ins is None:
            print 'Called by a class.'
            return lambda : typ.__name__
        else:
            print 'Called by an instance.'
            return lambda : ins.__class__.__name__
        
class X(object):
    id = Desc()

x = X()
print x.id()
print X.id()

Output:

Called by an instance.
X
Called by a class.
X

I have no idea what's your actual use case is, but you can do something like this using a descriptor:

class Desc(object):

    def __get__(self, ins, typ):
        if ins is None:
            print 'Called by a class.'
            return lambda : typ.__name__
        else:
            print 'Called by an instance.'
            return lambda : ins.__class__.__name__

class X(object):
    id = Desc()

x = X()
print x.id()
print X.id()

Output

Called by an instance.
X
Called by a class.
X