擅长:python、mysql、java
<p><a href="http://docs.python.org/library/itertools.html#recipes" rel="nofollow">itertools documentation</a>的配方就是这样:</p>
<pre><code>def unique_justseen(iterable, key=None):
"List unique elements, preserving order. Remember only the element just seen."
# unique_justseen('AAAABBBCCDAABBB') > A B C D A B
# unique_justseen('ABBCcAD', str.lower) > A B C A D
return imap(next, imap(itemgetter(1), groupby(iterable, key)))
</code></pre>
<p>虽然作为生成器表达式可能更易读:</p>
^{pr2}$
<p>您可以这样使用:</p>
<pre><code>for line in unique_justseen(fifoopen):
print line
</code></pre>