擅长:python、mysql、java
<p>短进近:</p>
<pre><code>import re
text = "the women marathon unknown introduced at the summer olympics los angeles usa and unknown won"
matches = re.finditer('(\S+\s+){2}(?=unknown)', text)
for m in matches:
print(m.group())
</code></pre>
<p>输出:</p>
<pre><code>women marathon
usa and
</code></pre>