擅长:python、mysql、java
<pre><code>>>> {key: {l: d.get(key).get(l) for l in lst} for key, lst in to_check.items()}
{'host': {'d': 'd1', 'v': 'v1'}, 'ether': {'sv': 'sv2', 'd': 'd2', 'v': 'v2'}}
</code></pre>
<p>与<code>[]</code>相比,使用<code>get</code>更安全,因为它提供了更大的灵活性,例如,如果键<code>x</code>不存在(我刚刚将其添加到<code>to_check</code>),则可以在<code>get</code>中设置另一个值以提供默认值:</p>
<pre><code>>>> {key: {l: d.get(key, 'Does Not Exist').get(l, 'Does Not exit') for l in lst} for key, lst in to_check.items()}
{'host': {'x': 'Does Not exit', 'd': 'd1', 'v': 'v1'}, 'ether': {'sv': 'sv2', 'd': 'd2', 'v': 'v2'}}
</code></pre>