擅长:python、mysql、java
<p>使用<code>collections</code>模块和<code>Counter</code>很简单。你知道吗</p>
<pre><code>from collections import Counter
common = Counter(yourList).items()
average = [(a, float(b) / len(common)) for (a,b) in common]
</code></pre>
<p>在给定列表中运行的结果:</p>
<pre><code>>>> average
[('AA11', 0.5), ('AA33', 0.25), ('AA22', 0.25), ('AA44', 0.5)]
</code></pre>