擅长:python、mysql、java
<p><strong>列表理解</strong>更快,因为它针对Python <code>interpreter</code>进行了优化,以便在<code>looping</code>期间发现可预测的模式。除了<code>list comprehensions</code>的语法优势外,它们通常与<code>map</code>的等效用法一样快或更快</p>
<pre><code>data = {'Common': {'height': 165, 'weight': 70, 'measure': ['cm', 'kg']},
'Man': 'handsome',
'Woman': {'feature': 'pretty', 'weight': 50},
'Dog': {'feature': 'barks', 'height': 10, 'weight': 20}}
for k, v in data.items():
if isinstance(v, dict):
data[k.upper()] = data.pop(k)
</code></pre>
<p><strong>输出></强></p>
<pre><code>data = {'COMMON': {'height': 165, 'weight': 70, 'measure': ['cm', 'kg']},
'Man': 'handsome',
'WOMAN': {'feature': 'pretty', 'weight': 50},
'DOG': {'feature': 'barks', 'height': 10, 'weight': 20}}
</code></pre>