擅长:python、mysql、java
<p>嵌套字典理解在这里很方便:</p>
<pre><code>>>> FlowDict = {(key1,key2):value for key1 in d for key2,value in d[key1].items()}
>>> FlowDict
{('AL', 'FL'): 1,
('AL', 'GA'): 0,
('AL', 'MS'): 0,
('AL', 'TN'): 0,
('AR', 'LA'): 0,
('AR', 'MO'): 0,
('AR', 'MS'): 0,
('AR', 'OK'): 0,
('AR', 'TN'): 16,
('AR', 'TX'): 0}
</code></pre>