擅长:python、mysql、java
<p>较短的备选方案:</p>
<pre><code>[{baz['id']: {quux['takenid']: quux['lib']}}
for foo in d
for k, v in foo.items()
for bar in v
for kk, vv in bar.items()
for baz in vv if 'library' in baz and baz['library']
for quux in baz['library']
]
# => [{'1': {'2': 'man'}}, {'3': {'0': 'woman'}}, {'3': {'1': 'ghost'}}, {'3': {'4': 'monster'}}]
</code></pre>
<p>这里,<code>if 'library' in baz and baz['library']</code>将检查<code>library</code>键是否存在并且不为空。你知道吗</p>