擅长:python、mysql、java
<p>更改为:</p>
<pre><code>u_names = [j['name'] for i in data for j in i if j['age'] > 21]
</code></pre>
<p><code>data</code>是一个嵌套列表<code>j</code>是内部实际迭代的<code>dict</code>对象</p>
<p>如果将对象重命名为更具描述性,则会看到结构:</p>
<pre><code>u_names = [
inner_dict['name']
for inner_list in data
for inner_dict in inner_list
if inner_dict['age'] > 21
]
</code></pre>
<p>也就是说:</p>
<pre><code>for inner_list in data:
for inner_dict in inner_list:
if inner_dict['age'] > 21:
return inner_dict['name']
</code></pre>