面向对象 类， 对象 属性和方法 封装 数据隐藏 继承(object) 代码复用 多态 接口重用 magic method魔术方法 构造对象 运算符 类的展现 类的属性访问

构造函数 def __init__ 析构函数 def __del__  新式类(object)和老式类

public   name protected  _age private __weight

public protected private  method @classmethod @property

调用父类方法 super(superclass, self).method(args) superClass.method(args)  isinstance issubclass 多继承

对象实例化：创建对象 -》初始化对象 __new__(cls) __init__(self) 回收对象 __del__(self)  运算符 __cmp__(self, other) __eq__(self, other) __lt__(self, other) __gt__(self, other) __add__(self, other) __sub__(self, other) __mul__(self, other) __div__(self, other) __or__(self, other) __and__(self, other)  转为字符串 __str__ -> 适合人看 __repr__ -> 适合机器看 -> eval()直接运行 __unicode__ __dir__  设置对象属性 def __setattr__(self, name, value)  self.__dict__[name] =value  错误设置，默认递归1000次 def __setattr__(self, name, value):  setattr(self, name, value)  查询对象属性 __getattr__(self, name)  没有被查询到调用 __getattribute__(self, name)  每次查询都会调用  删除对象属性 __delattr__(self, name)

# -*- coding: utf-8 -*- # 父类 class Person(object):  count = 0   # 新建对象  def __new__(cls, *args, **kwargs):  print("call __new__")  return super(Person, cls).__new__(cls, *args, **kwargs)   # 初始化  def __init__(self, name, age, weight):  print("call __init__")  self.name = name  self._age = age  self.__weight = weight  Person.count += 1   @classmethod  def get_count(cls):  return cls.count   @property  def weight(self):  return self.__weight   def say_hello(self):  print("hello")  # 子类 class EarthPerson(Person):  def __init__(self, name, age, weight, language):  super(EarthPerson, self).__init__(name, age, weight)  self.language = language   # 重写父类方法  def say_hello(self):  print("hello, my name is %s"%self.name)   def introduce(person):  if isinstance(person, Person):  person.say_hello()  if __name__ == '__main__':   p1 = Person("tom", 23, 60)  """  call __new__  call __init__  """   p2 = EarthPerson("jack", 24, 65, "English")  """  call __new__  call __init__  """   print(p1)  # <__main__.Person object at 0x106fb2350>   print(p1.__dict__)  # {'_age': 23, 'name': 'tom', '_Person__weight': 60}   print(dir(p1))  """  ['_Person__weight', '__class__', '__delattr__', '__dict__',  '__doc__', '__format__', '__getattribute__', '__hash__',  '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__',  '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__',  '__weakref__', '_age', 'count', 'get_count', 'name', 'say_hello', 'weight']  """   print(p1.name)  # tom  print(p1._age)  # 23  print(p1._Person__weight)  # 60  print(p1.weight)  # 60  print(Person.count)  # 2  print(Person.get_count())  # 2  p1.say_hello()  # hello    print(p2)  #  <__main__.EarthPerson object at 0x106fb2390>  print(issubclass(EarthPerson, Person))  # True  print(isinstance(p2, Person))  # True  p2.say_hello()  # hello, my name is jack  introduce(p2)  # hello, my name is jack  introduce(p1)  # hello

class Point(object):  def __init__(self, x, y):  self.x = x  self.y = y   def __eq__(self, other):  if isinstance(other, Point):  if self.x == other.x and self.y == other.y:  return True  else:  return False  else:  raise Exception("the type must be Ponit")   def __add__(self, other):  if isinstance(other, Point):  x = self.x + other.x  y = self.y + other.y  return Point(x, y)  else:  raise Exception("the type must be Ponit")   def __str__(self):  return "Ponit(x={x}, y={y})".format(x=self.x, y=self.y)   def __dir__(self):  return self.__dict__.keys()   def __getattribute__(self, name):  # return getattr(self, name) 错误  # return self.__dict__[name] 错误  return super(Point, self).__getattribute__(name)   def __setattr__(self, name, value):  # setattr(self, name, value) 错误  self.__dict__[name] = value   if __name__ == '__main__':   point1 = Point(1, 2)  point2 = Point(1, 2)  print(point1 == point2)  # True  print(point1 + point2)  # Ponit(x=2, y=4)  print(dir(point1))  # ['x', 'y']