class Pizza:
	def __init__(self, radius, ingredients):
		self.ingredients = ingredients
		self.radius = radius

	def __repr__(self):
		return f'Pizza({self.ingredients})'

	def area(self):
		return self._circle_area(self.radius)

	@staticmethod
	def _circle_area(r):
		return r ** 2 * math.pi

Pizza(4.5, ['cheese']).area()
