擅长:python、mysql、java
<p>这样可以保持秩序</p>
<pre><code>from collections import defaultdict
alist = [11,12,13,11,15]
blist = ['A', 'A', 'B', 'A', 'B']
d = defaultdict(list)
seen = defaultdict(set)
for k, v in zip(blist, alist):
if v not in seen[k]:
d[k].append(v)
seen[k].add(v)
print d
</code></pre>
<hr/>
<pre><code>defaultdict(<type 'list'>, {'A': [11, 12], 'B': [13, 15]})
</code></pre>