class A:
    def __init__(self, a, b, c):
        self.a = a
        self.b = b
        self.c = c
        self.a1, self.a2, self.a3, self.a4 = range(4)

class X:
    def __del__(self):
        for i in range(20):
            setattr(a, 'x'+str(i), i)

a = A(1, 2, X())
a.c = 42