擅长:python、mysql、java
<p>引发此错误的原因是集合只能包含不可变类型。或集合是可变的。然而,这里有<code>frozenset</code>类型:</p>
<pre><code>In [4]: a, b = {1,2,3}, {2,3,4}
In [5]: set([a,b])
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-5-6ca6d80d679c> in <module>()
----> 1 set([a,b])
TypeError: unhashable type: 'set'
In [6]: a, b = frozenset({1,2,3}), frozenset({2,3,4})
In [7]: set([a,b])
Out[7]: {frozenset({1, 2, 3}), frozenset({2, 3, 4})}
</code></pre>