def test_area(r):
circle = Circle(1)
circle.radius = r
assert circle.area == np.pi * r ** 2
def test_invalid_radius_setter():
circle = Circle(1)
with pytest.raises(ValueError):
circle.radius = -1
def test_perimeter(r):
circle = Circle(1)
circle.radius = r
assert circle.perimeter == 2 * np.pi * r
assert circle.circumference == 2 * np.pi * r
def test_radius_getter_setter(r):
"""Test getting and setting the radius."""
circle = Circle(r)
assert circle.radius == r
circle.radius = r + 1
assert circle.radius == r + 1