擅长:python、mysql、java
<p>您可以将每个字典转换为<a href="https://docs.python.org/2/library/collections.html#collections.Counter" rel="nofollow">^{<cd1>}</a>,其中month是键,value是<code>s['sum']</code>,然后将它们相加:</p>
<pre><code>from collections import Counter
sum((Counter({x['datestart'].month: x['sum']}) for x in summary), Counter())
# Counter({4: Decimal('5000000.00'), 3: Decimal('400000.00')})
</code></pre>
<p>请注意,如果需要区分月份和年份,请改用<code>{(x['datestart'].month, x['datestart'].year): x['sum']}</code>。你知道吗</p>