擅长:python、mysql、java
<p>不需要正则表达式;普通编程结构可以很好地处理这类问题。编写循环并添加条件:</p>
<pre><code>s = 'all in all day in and day out bit by bit good good good'
words = s.split()
result = []
for i in range(len(words) - 2):
if words[i] == words[i+2] and words[i] != words[i+1]:
result.append(words[i])
print(result) # ['all', 'bit']
</code></pre>