Python的instance方法,class方法,static方法和abstract方法。
实例方法的声明只需将第一个参数指定为self, 静态方法无参数要求。而类方法需将第一个参数指定为类cls。抽象方法是定义在基类中的一种方法,不提供任何实现。

下面来看方法实现:

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# -*- coding: utf-8 -*-
class Material(object):
def __init__(self, cheese='', vegetables='', meat=''):
self.cheese = cheese
self.vegetables = vegetables
self.meat = meat
def get_cheese(self):
return self.cheese
def get_vegetables(self):
return self.vegetables
def get_meat(self):
return self.meat
class Pizza(object):
def __init__(self, size):
self.size = size
def get_size(self):
return self.size
@staticmethod
def pure_material(x):
return 'Pure Pizza: %s' % x
@staticmethod
def mix_material(x, y):
return 'Mix Pizza: %s + %s' % (x, y)
@classmethod
def cook_vegetable(cls, material):
return cls.pure_material(material.get_vegetables())
@classmethod
def cook_meat(cls, material):
return cls.mix_material(material.get_cheese(), material.get_meat())
material = Material('Cheese', 'Tomatoes', 'Beaf')
p = Pizza(30)
print('Pizza size', p.get_size())
print(Pizza.cook_vegetable(material))
print(Pizza.cook_meat(material))
Output:
Pizza size 30
Pure Pizza: Tomatoes
Mix Pizza: Cheese + Beaf

抽象方法,我们可以通过一个BasePizza来实现。

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# -*- coding: utf-8 -*-
import abc
class BasePizza(object):
__abstract__ = True
__metaclass__ = abc.ABCMeta
default_material = ['wheat']
@classmethod
@abc.abstractmethod
def get_material(cls):
return cls.default_material
class AdvancePizza(BasePizza):
def __init__(self, size):
self.size = size
def get_size(self):
return self.size
def get_material(self):
return ['egg'] + ['meat'] + ['friut'] + super(AdvancePizza, self).get_material()
p = AdvancePizza(30)
print(p.get_material())

References:

The definitive guide on how to use static, class or abstract methods in Python