擅长:python、mysql、java
<p>创建形式为<code>year: [list, number of quartals]</code>的dict<code>d = {}</code></p>
<p>迭代原始列表</p>
<pre class="lang-py prettyprint-override"><code>for yr, x,y,z in data:
if yr not in d:
d[yr] = [[yr, x, y, z], 1]
# now make changes
else:
a = d[yr]
e, n = a
e[1] += x
e[2] = max(e[2], y)
e[3] = min(e[3], z)
a[1] += 1
</code></pre>
<p>现在再次迭代<code>d</code>除以<code>e[1] / a[1]</code>得到平均值<br/>
并将<code>e</code>放入结果列表中</p>