class Test:
    x = 10
    def __init__(self):
        self.y = 20
t1 = Test()
t2 = Test()
print('t1:', t1.x, t1.y)
print('t2:', t2.x, t2.y)
t1.x = 888
t1.y = 999
print('t1:', t1.x, t1.y)
print('t2:', t2.x, t2.y)   