Question

I have this code:

class X(object):
    x = 10
    def test_x(self):
        return self.x

class Y(X):
    def test_y(self):
        return self.x

y = Y()
y.test_y()      # works fine

But when I construct a new object z based on X using type :

z = type('Z', (X,), dict(z=1))
z.x             # works fine
z.test_x()      # gives a TypeError : 

unbound method test_x() must be called with Z instance as first argument (got nothing instead).
How can I solve it.

UPDATE

With the help and understanding of Martijn, this is how I solved it:

z = type('Z', (X,), dict(z=1))()
z.test_x() 

Answer 1

z is a class, not an instance. Create an instance instead:

z().test_x()

What you did was the equivalent of:

class Z(X):
    z = 1

z = Z
z.test_x()