擅长:python、mysql、java
<p>不需要负的lookback来匹配<code>2017</code>的第二个实例。你知道吗</p>
<p>您可以使用非贪婪量词:</p>
<pre><code>^.*?2017.*?(2017)
</code></pre>
<p><a href="https://regex101.com/r/UyG2aL/1" rel="nofollow noreferrer">RegEx Demo</a></p>
<p>二审在一组抓获</p>
<p><strong>代码:</strong></p>
<pre><code>>>> str = 'car price is $2017 and manufactured in 2017 and make is Honda'
>>> print re.findall(r'^.*?2017.*?(2017)', str)
['2017']
</code></pre>