擅长:python、mysql、java
<p>Python没有<code>OrderedSet</code>;通常我们用<a href="http://docs.python.org/2/library/collections.html#collections.OrderedDict" rel="noreferrer">^{<cd2>}</a>来伪装它。在</p>
<p>例如:</p>
<pre><code>>>> from collections import OrderedDict
>>> s = "mathematics"
>>> alpha = "abcdefghiklmnopqrstuvwxyz"
>>> d = OrderedDict.fromkeys(s+alpha)
>>> d
OrderedDict([('m', None), ('a', None), ('t', None), ('h', None), ('e', None), ('i', None), ('c', None), ('s', None), ('b', None), ('d', None), ('f', None), ('g', None), ('k', None), ('l', None), ('n', None), ('o', None), ('p', None), ('q', None), ('r', None), ('u', None), ('v', None), ('w', None), ('x', None), ('y', None), ('z', None)])
>>> ''.join(d)
'matheicsbdfgklnopqruvwxyz'
</code></pre>
<p>这并不像<code>OrderedSet</code>那样有效,但对于政府工作来说,这往往足够接近。在</p>