Python多态
多态:在编辑时无法确定状态，在运行时才确定。由于Python为动态语言，参数类型没定，所以本身即是多态的1：由继承实现多态
1 class Animal:
2 def move(self):
3 print('Animal is moving')
4
5 class Dog:
6 def move(self):
7 print('Dog is running')
8
9 class Fish:
10 def move(self):
11 print('Fish is swimming')
12
13 Animal().move()
14 Dog().move()
15 Fish().move()
结果：
Animal is moving
Dog is running
Fish is swimming
2：通过重载实现多态
1 #在子类中：
2
3 class child:
4 def start(self):
5 print('....')
6 super().start()
7 print('......')
3：动态语言特性（参数类型不定）与鸭子模型
例子1：类实例为参数
class Animal:
def move(self):
print('Animal is moving')
class Dog:
def move(self):
print('Dog is running')
class Fish:
def move(self):
print('Fish is swimming')
def move(obj): #obj为实例参数
obj.move()
move(Animal())
move(Dog())
move(Fish())
----------------类作为参数-------------
class Moveable:
def move(self):
print('Move...')
class MoveOnFeet(Moveable):
def move(self):
print("Move on Feet.")
class MoveOnWheel(Moveable):
def move(self):
print("Move on Wheels.")
#-------------------------------------------------------------------
class MoveObj:
def set_move(self,moveable): #moveable为类
self.moveable = moveable()
def move(self):
self.moveable.move() #通过moveable实例调用到不同的类
class Test:
def move(slef):
print("I'm Fly.")
if __name__ == '__main__':
m = MoveObj()
m.set_move(Moveable)
m.move()
m.set_move(MoveOnFeet)
m.move()
m.set_move(MoveOnWheel)
m.move()
m.set_move(Test)
m.move()
结果：
Move...
Move on Feet.
Move on Wheels.
I'm Fly.
例子2：函数名为参数
def movea():
print('Move a.')
def moveb():
print('Move b.')
class MoveObj:
def __init__(self,moveable): #moveable为函数参数
self.moveable = moveable #绑定函数名参数
self.moveable() #调用函数
if __name__ == '__main__':
a = MoveObj(movea)
b = MoveObj(moveb)
结果：
move a
move b
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