擅长:python、mysql、java
<p>答案是肯定的,您需要重新定义<code>__hash__()</code>:</p>
<pre><code>>>> class A(object):
... def __init__(self, data=''):
... self.data = data
... def __eq__(self, another):
... return hasattr(another, 'data') and self.data == another.data
... def __hash__(self):
... return hash(self.data)
...
>>> a1, a2, a3 = A('foo'), A('foo'), A('bar')
>>> d = {a1: 'foo'}
>>> d[a1]
'foo'
>>> d[a2]
'foo'
>>> d[a3]
Traceback (most recent call last):
File "", line 1, in
KeyError: __main__.A object at 0x927d0>
</code></pre>
<p>正如在另一个注释中所解释的,<code>__hash__</code>的默认实现只是简单的标识,所以如果您想使它更复杂,就需要显式地定义它。</p>