python class with or without "in

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python class and inheritance of object

To make the concept as concise as possible, I won't discuss things too much around the historical fact, instead, let me just state the real use of python class in inheritance of object

To understand we must first know there are python2 and python3 versions and the class style contains new style and classic style.

• Difference between new style and classic style
  • There is something around Depth-First Search and Breadth-First Search, and the new tends to be inclined of Breadth-First where old tends to be inclined of Depth-First. For more details of the difference between this 2, visite this link.
  • Python2 uses either old or new where Python3 uses only new as its default form.
• HOW-TO implements old new for p2, p3 respectively.
  • In python2

  # Python2.x中，默认都是经典类，只有显式继承了object才是新式类，即：
  class Person(object):pass               # 新式类写法
  class Person():pass                     # 经典类写法
  class Person:pass                       # 经典类写法
  

  • in python3

  # 在Python 3.x中取消了经典类，默认都是新式类，
  # 并且不必显式的继承object，也就是说：
  class Person(object):pass
  class Person():pass
  class Person:pass
  # 三种写法并无区别，推荐第一种