擅长:python、mysql、java
<p>我认为使用try-catch不适合这个任务。只需使用操作符<code>in</code></p>
<pre><code>requestedSong=input("Enter song from playlist: ")
if requestedSong in songDictionary:
print songDictionary[requestedSong]
else:
print 'song not found'
</code></pre>
<p>我强烈建议你阅读这篇文章
<a href="http://www.tutorialspoint.com/python/python_dictionary.htm" rel="nofollow noreferrer">http://www.tutorialspoint.com/python/python_dictionary.htm</a><br/>
也可以查看以下问题:
<a href="https://stackoverflow.com/questions/1602934/check-if-a-given-key-already-exists-in-a-dictionary?rq=1">check if a given key exists in dictionary</a><br/>
<a href="https://stackoverflow.com/questions/1835756/using-try-vs-if-in-python">try vs if</a></p>