def test_set_diameter():
c = Circle(2)
assert c.diameter == 4
c.diameter = 10
assert c.radius == 5
def test_setter_diameter():
c = Circle(4)
c.diameter = 2
print(c.diameter, "and", c.radius)
assert c.radius == 1
def test_setter_diameter():
c = Circle(4)
c.diameter = 2
assert c.radius == 1