擅长:python、mysql、java
<p>假设数据库查询以这种方式返回输出:<code>database = {"Belgium":["Brussels", "Gent", "Bruge"], "Germany":["Berlin", "Frankfurt"]}</code>。您可以使用列表理解来实现您的目标:</p>
<pre><code>lvls = {"Belgium": "EUR", "Germany": "EUR"}
database = {"Belgium":["Brussels", "Gent", "Bruge"], "Germany":["Berlin", "Frankfurt"]}
one = [(y,x,lvls[x]) for x,sub in database.items() for y in sub]
print(one)
</code></pre>
<blockquote>
<p>Output</p>
</blockquote>
<pre><code>[('Brussels', 'Belgium', 'EUR'), ('Gent', 'Belgium', 'EUR'), ('Bruge', 'Belgium', 'EUR'), ('Berlin', 'Germany', 'EUR'), ('Frankfurt', 'Germany', 'EUR')]
</code></pre>