擅长:python、mysql、java
<p>因为您的模式包含捕获组。你知道吗</p>
<p>从<a href="https://docs.python.org/3/library/re.html#re.findall" rel="noreferrer">^{<cd1>}</a>:</p>
<blockquote>
<p>If one or more groups are present in the pattern, return a list of groups; this will be a list of tuples if the pattern has more than one group.</p>
</blockquote>
<p>如果您想摆脱它们,请使用以下模式:</p>
<pre><code>r"(?:Cl|H|O|C|N)[0-9]*"
</code></pre>
<p>它完全删除(不需要的)外部捕获组,并为alpha字符使用非捕获组。你知道吗</p>
<pre><code>>>> re.findall(r"(?:Cl|H|O|C|N)[0-9]*", my_string)
['C2', 'H6', 'O']
</code></pre>