Python Design Patterns 简明教程
Object Oriented Concepts Implementation
在本章中，我们将重点关注使用面向对象概念的模式及其在 Python 中的实现。当我们围绕语句块设计我们的程序时，这些语句块围绕函数处理数据，这称为过程化编程。在面向对象编程中，有两个称为类和对象的主实例。
How to implement classes and object variables?
类和对象变量的实现如下 −
class Robot:
population = 0
def __init__(self, name):
self.name = name
print("(Initializing {})".format(self.name))
Robot.population += 1
def die(self):
print("{} is being destroyed!".format(self.name))
Robot.population -= 1
if Robot.population == 0:
print("{} was the last one.".format(self.name))
else:
print("There are still {:d} robots working.".format(
Robot.population))
def say_hi(self):
print("Greetings, my masters call me {}.".format(self.name))
@classmethod
def how_many(cls):
print("We have {:d} robots.".format(cls.population))
droid1 = Robot("R2-D2")
droid1.say_hi()
Robot.how_many()
droid2 = Robot("C-3PO")
droid2.say_hi()
Robot.how_many()
print("\nRobots can do some work here.\n")
print("Robots have finished their work. So let's destroy them.")
droid1.die()
droid2.die()
Robot.how_many()