python学习笔记2（对象）

对象的属性不能继承。
方法可以调用没有的参数或方法，但运行时会报错。

@[email protected]标记的方法可以当作属性来用。

class Animal(object):
	def __init__(self):
		self.age="yi"
	def run(self):
		print(self.name,"is running")
class Peple(object):
	def run(self):
		print("peple is running")
def run2(xx):
	xx.run()

class Dog(Animal):
	__name=""
	__slots__ = ('age') # 用tuple定义允许绑定的属性名称
	def __init__(self):
		self.a , self.b = 0 , 1
	def __str__(self):
		return 'Dog (name: %s)' % self.name   #  __name一样
	def __iter__(self):
		return self
	def __next__(self):
		self.a ,self.b = self.b , self.a+self.b
		if self.a>100:
			raise StopIteration()
		return self.a
	def __getitem__(self,n):
		d = Dog()
		for x in range(n):
			next(d)
		return d.a
	@property
	def name(self):
		return self.__name
	@name.setter
	def set_name(self,value):
		if len(value)>3:
			raise ValueError("长度不能大于三")
		self.__name = value
	@property
	def english_name(self):
		return self.__name+"zhi"
peple = Peple()
dog = Dog()
run2(peple)
run2(dog)#证明多态性，只要有run方法即可
print("origin name:",dog.name)
dog.set_name="liu"
print("after set name:",dog.name)
dog.run()
print(dog)
print("english name:",dog.english_name)
for n in dog:
	print(n)
print("getitem=====5n=",dog[5])
dog.set_name="我是五大锤"
print("after set name:",dog.name)

创建类

def fn(self, name='world'): # 先定义函数
   print('Hello, %s.' % name)
Hello = type('Hello', (object,), dict(hello=fn)) # 创建Hello class
h = Hello()
h.hello()