fork download
copy 
  1. #!/usr/bin/env python
  2.  
  3. from abc import ABCMeta, abstractmethod
  4.  
  5. def subclasshook(required):
  6.     """Generates a subclass hook based on a simple check for attributes."""
  7.     def __subclasshook__(cls, Check):
  8.         rtn = True
  9.         for r in required:
  10.             if not any(r in vars(BaseClass) for BaseClass in Check.__mro__):
  11.                 rtn = NotImplemented
  12.         return rtn
  13.     return __subclasshook__
  14.  
  15. class Duck(object):
  16.     def __init__(self, fly, quack):
  17.         self._fly_behaviour = fly
  18.         self._quack_behaviour = quack
  19.  
  20.     def fly(self):
  21.         return self._fly_behaviour.fly()
  22.  
  23.     def quack(self):
  24.         return self._quack_behaviour.quack()
  25.  
  26.     def swim(self):
  27.         print "All ducks float, even decoys!"
  28.  
  29. class MallardDuck(Duck):
  30.     def __init__(self):
  31.         Duck.__init__(self, Fly(), Quack())
  32.         print "I'm a real Mallard Duck"
  33.  
  34. class ModelDuck(Duck):
  35.     def __init__(self):
  36.         Duck.__init__(self, FlyNoWay(), SqueakQuack())
  37.         print "I'm a Model Duck"
  38.  
  39. class DecoyDuck(Duck):
  40.     def __init__(self):
  41.         Duck.__init__(self, FlyNoWay(), MuteQuack())
  42.         print "I'm a Decoy Duck"
  43.  
  44. class FlyBehavior:
  45.     __metaclass__ = ABCMeta
  46.  
  47.     @abstractmethod
  48.     def fly(self):
  49.         pass
  50.  
  51.     __subclasshook__ = classmethod(subclasshook(["fly"]))
  52.  
  53. class Fly(FlyBehavior):
  54.     def fly(self):
  55.         print "I'm flying!!"
  56.  
  57. class FlyNoWay(FlyBehavior):
  58.     def fly(self):
  59.         print "I can't fly"
  60.  
  61. class FlyRocketPowered(FlyBehavior):
  62.     def fly(self):
  63.         print "I'm flying with a rocket!"
  64.  
  65. class QuackBehavior:
  66.     __metaclass__ = ABCMeta
  67.  
  68.     @abstractmethod
  69.     def quack(self):
  70.         pass
  71.  
  72.     __subclasshook__ = classmethod(subclasshook(["quack"]))
  73.  
  74. class Quack(QuackBehavior):
  75.     def quack(self):
  76.         print "Quack"
  77.  
  78. class MuteQuack(QuackBehavior):
  79.     def quack(self):
  80.         print "<< Silence >>"
  81.  
  82. class SqueakQuack(QuackBehavior):
  83.     def quack(self):
  84.         print "Squeak"
  85.  
  86. if __name__ == "__main__":
  87.  
  88.     print '#'*80
  89.     print "Mallard Duck"
  90.     print '#'*80
  91.     mallard = MallardDuck()
  92.     mallard.quack()
  93.     mallard.fly()
  94.  
  95.     print '#'*80
  96.     print "Model Duck"
  97.     print '#'*80
  98.     model = ModelDuck()
  99.     model.fly()
  100.     model._fly_behaviour = FlyRocketPowered()
  101.     model.fly()
  102.  
  103.     print '#'*80
  104.     print "Decoy Duck"
  105.     print '#'*80
  106.     decoy = DecoyDuck()
  107.     decoy.fly()
  108.     decoy.quack()
Success #stdin #stdout 0.08s 10824KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
################################################################################
Mallard Duck
################################################################################
I'm a real Mallard Duck
Quack
I'm flying!!
################################################################################
Model Duck
################################################################################
I'm a Model Duck
I can't fly
I'm flying with a rocket!
################################################################################
Decoy Duck
################################################################################
I'm a Decoy Duck
I can't fly
<< Silence >>
https://ideone.com/Owgfjj
language:
Python (cpython 2.7.16)
created:
11 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!