擅长:python、mysql、java
<p>有你的单子吗</p>
<pre><code>l = [{'COUNTRY': 'UK', 'STUDENT': 'JOHN'}, {'COUNTRY': 'PT', 'STUDENT':'PEDRO'}, {'COUNTRY': 'UK', 'STUDENT': 'KYLE'}, {'COUNTRY': 'IT', 'STUDENT':'PIRLO'}, {'COUNTRY': 'PT', 'STUDENT':'ANA'}, {'COUNTRY': 'FR', 'STUDENT':'VITO'}, {'COUNTRY': 'FR', 'STUDENT':'LOUIS'}]
</code></pre>
<p>您可以首先提取国家/地区的所有值:</p>
^{pr2}$
<p>然后您可以使用来自<code>collections</code>模块的<code>Counter</code>:</p>
<pre><code>In [19]: m = Counter(k)
Out[19]: Counter({'FR': 2, 'IT': 1, 'PT': 2, 'UK': 2})
</code></pre>
<p>要获取轴:</p>
<pre><code>In [20]: countries = m.keys()
In [21]: frequency = m.values()
In [22]: countries
Out[22]: ['FR', 'PT', 'UK', 'IT']
In [23]: frequency
Out[23]: [2, 2, 2, 1]
</code></pre>