擅长:python、mysql、java
<p>始终可以使用<a href="https://docs.python.org/library/functions.html#sum" rel="nofollow noreferrer">^{<cd1>}</a>和条件理解:</p>
<pre><code>num_males = sum(1 for subdict in marged if subdict['Gender'] == 'Male')
</code></pre>
<p>它迭代<code>marged</code>中的所有词典(这不应该称为<code>merged</code>吗?)并检查<code>'Gender'</code>是否为<code>'Male'</code>。您还可以通过以下方式检查5岁到10岁之间的人数:</p>
<pre><code>num_age_5_to_10 = sum(1 for subdict in marged if 5 <= subdict["Age"] <= 10)
</code></pre>
<p>当然,也可以用布尔条件替换<code>1</code>(因为<code>True</code>等价于<code>1</code>,而<code>False</code>等价于<code>0</code>):</p>
<pre><code>num_males = sum(subdict['Gender'] == 'Male' for subdict in marged)
num_age_5_to_10 = sum(5 <= subdict["Age"] <= 10 for subdict in marged)
</code></pre>