<p>两个对象的简单比较表明dictionary远比简单类复杂:</p>
<pre><code>>>> dt = {}
>>> dir(dt)
['__class__', '__cmp__', '__contains__', '__delattr__', '__delitem__', '__doc__',
'__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__',
'__hash__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__ne__',
'__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setitem__',
'__sizeof__', '__str__', '__subclasshook__', 'clear', 'copy', 'fromkeys', 'get',
'has_key', 'items', 'iteritems', 'iterkeys', 'itervalues', 'keys', 'pop', 'popitem',
'setdefault', 'update', 'values', 'viewitems', 'viewkeys', 'viewvalues']
</code></pre>
<p>反对:</p>
<pre><code>>>> class O(object):
... var1 = 'asdfasdfasfasdfasdfasdfasdf'
... var2 = 255
...
>>> o = O()
>>> dir(o)
['__class__', '__delattr__', '__dict__', '__doc__', '__format__',
'__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__',
'__reduce_ex__', '__repr__', '__setattr__', '__sizeof__',
'__str__', '__subclasshook__', '__weakref__', 'var1', 'var2']
</code></pre>