Python中有趣在__call__函数

class g_dpm(object):
def __init__(self, g):
self.g = g
def __call__(self, t):
return (self.g*t**2)/2

class Animal(object):
 def __init__(self, name, legs):
 self.name = name
 self.legs = legs
 self.stomach = [] 
 
 def __call__(self,food):
 self.stomach.append(food)
 
 def poop(self):
 if len(self.stomach) > 0:
 return self.stomach.pop(0)
 
 def __str__(self): 
 return 'A animal named %s' % (self.name) 
 
cow = Animal('king', 4) #We make a cow
dog = Animal('flopp', 4) #We can make many animals
print 'We have 2 animales a cow name %s and dog named %s,both have %s legs' % (cow.name, dog.name, cow.legs)
print cow #here __str__ metod work
 
#We give food to cow
cow('gras')
print cow.stomach
 
#We give food to dog
dog('bone')
dog('beef')
print dog.stomach
 
#What comes inn most come out
print cow.poop()
print cow.stomach #Empty stomach
 
'''-->output
We have 2 animales a cow name king and dog named flopp,both have 4 legs
A animal named king
['gras']
['bone', 'beef']
gras
[]
'''