擅长:python、mysql、java
<pre><code>my_lists = defaultdict(list)
for key,val in my_dict.items():
for key2,val2 in val.items():
my_lists[key2].append(val2)
def average(key_val):
key,val = key_val
return (key, sum(val)*1.0/len(val))
print dict(map(average,my_lists))
</code></pre>