基于Python __dict__与dir()的区别详解

#!/usr/bin/python# -*- coding: utf-8 -*-class A(object):  class_var = 1  def __init__(self):    self.name = 'xy'    self.age = 2  @property  def num(self):    return self.age + 10  def fun(self):pass  def static_f():pass  def class_f(cls):passif __name__ == '__main__':#主程序  a = A()  print a.__dict__  #{'age': 2, 'name': 'xy'}  实例中的__dict__属性  print A.__dict__    '''  类A的__dict__属性  {  '__dict__': <attribute '__dict__' of 'A' objects>, #这里如果想深究的话查看参考链接5  '__module__': '__main__',        #所处模块  'num': <property object>,        #特性对象   'class_f': <function class_f>,     #类方法  'static_f': <function static_f>,    #静态方法  'class_var': 1, 'fun': <function fun >, #类变量  '__weakref__': <attribute '__weakref__' of 'A' objects>,   '__doc__': None,            #class说明字符串  '__init__': <function __init__ at 0x0000000003451AC8>}  '''  a.level1 = 3  a.fun = lambda :x  print a.__dict__ #{'level1': 3, 'age': 2, 'name': 'xy','fun': <function <lambda> at 0x>}  print A.__dict__ #与上述结果相同  A.level2 = 4  print a.__dict__ #{'level1': 3, 'age': 2, 'name': 'xy'}  print A.__dict__ #增加了level2属性  print object.__dict__  '''  {'__setattr__': <slot wrapper '__setattr__' of 'object' objects>,   '__reduce_ex__': <method '__reduce_ex__' of 'object' objects>,   '__new__': <built-in method __new__ of type object at>,   等.....  '''

print dir(A)'''['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'age', 'class_f', 'class_var', 'fun', 'level1', 'level2', 'name', 'num', 'static_f']'''a_dict = a.__dict__.keys()A_dict = A.__dict__.keys()object_dict = object.__dict__.keys()print a_dict print A_dict print object_dict '''['fun', 'level1', 'age', 'name']['__module__', 'level2', 'num', 'static_f', '__dict__', '__weakref__', '__init__', 'class_f', 'class_var', 'fun', '__doc__']['__setattr__', '__reduce_ex__', '__new__', '__reduce__', '__str__', '__format__', '__getattribute__', '__class__', '__delattr__', '__subclasshook__', '__repr__', '__hash__', '__sizeof__', '__doc__', '__init__']'''#因为每个类都有一个__doc__属性，所以需要去重，去重后然后比较print set(dir(a)) == set(a_dict + A_dict + object_dict) #True