擅长:python、mysql、java
<p>在Python2.7(或更新版本)中,可以使用collections.Counter</p>
<p>collections.Counter()</p>
<p>计数器是将元素存储为字典键的容器,其计数存储为字典值</p>
<pre><code>import collections
a = [1,1,1,1,2,2,2,2,3,3,4,5,5]
counter=collections.Counter(a)
print(counter)
# Counter({1: 4, 2: 4, 3: 2, 5: 2, 4: 1})
</code></pre>