Python：试图修复缩进错误

Question

class Cylinder(object):
    self.pi = 3.14

    def __init__(self,height=1,radius=1):
        self.height = height
        self.radius = radius

    def volume(self):
        return self.pi * self.radius**2 * self.height

    def surface_area(self):
        pass

Answer 1

Remove self from the second line. self is used only inside class methods to access class instance. But class attributes declared on class-level apply not to single class instance, but to class itself and all its instances: so they do not require self .