擅长:python、mysql、java
<p>您可以使用<a href="http://docs.python.org/library/collections.html#collections.defaultdict" rel="noreferrer">^{<cd1>}</a>轻松完成此操作:</p>
<pre><code>def invert_dict(d):
inverted_dict = collections.defaultdict(set)
for actor, movies in d.iteritems():
for movie in movies:
inverted_dict.add(actor)
return inverted_dict
</code></pre>