human
I am working on the file "03_advanced/advanced_python_tricks.ipynb".
The first task is:
Mating
Can you write Python program for it?
assistant
#Here is the Python program you requested.

class Dog(object):
    color = "yellow"
    def __init__(self, name, size):
            self.name = name
            self.size = size
            
    def __add__(self, dog):
        if not isinstance(dog, Dog):
            raise TypeError
        return Dog(self.name + " " + dog.name, (self.size + dog.size)/2)
    
    def bark(self):
        print 'whoof, whoof!'

b = Dog("blitzer", 100)
dog = b + p
dog.bark()
print dog.name
print dog.size