擅长:python、mysql、java
<p>假设数据库的输出如下所示:</p>
<pre><code>cities = [('Brussel', 'Belgium'), ('Gent', 'Belgium'), ('Frankfurt', 'Germany')]
</code></pre>
<p>然后你可以用你已经有的口述,像这样:</p>
<pre><code>((city, country, lvls[country]) for city, country in cities)
</code></pre>