python2中为什么在进行类定义时最好

# -.- coding:utf-8 -.-
# __author__ = 'zhengtong'


class Person:
    """
    不带object
    """
    name = "zhengtong"


class Animal(object):
    """
    带有object
    """
    name = "chonghong"

if __name__ == "__main__":
    x = Person()
    print "Person", dir(x)

    y = Animal()
    print "Animal", dir(y)

Person ['__doc__', '__module__', 'name']
Animal ['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', 
'__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', 
'__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'name']