擅长:python、mysql、java
<p>小心一点:改变L</p>
<pre><code>>>> allkeys = frozenset().union(*L)
>>> for i in L:
... for j in allkeys:
... if j not in i:
... i[j]=0
>>> L
[{0: 1, 1: 7, 2: 3, 3: 0, 4: 8}, {0: 3, 1: 0, 2: 6, 3: 0, 4: 0}, {0: 0, 1: 2, 2:
0, 3: 0, 4: 6}, {0: 2, 1: 0, 2: 0, 3: 2, 4: 0}]
</code></pre>