<p>你需要这样转义<code>\</code>:</p>
<pre><code>>>> import re
>>> x = 'the meaning\nof life'
>>> re.sub("([,\w])\n(\w)", "\1 \2", x)
'the meanin\x01 \x02f life'
>>> re.sub("([,\w])\n(\w)", "\\1 \\2", x)
'the meaning of life'
>>> re.sub("([,\w])\n(\w)", r"\1 \2", x)
'the meaning of life'
>>>
</code></pre>
<p>如果不转义,则输出为<code>\1</code>,因此:</p>
<pre><code>>>> '\1'
'\x01'
>>>
</code></pre>
<p>这就是为什么我们需要使用<code>'\\\\'</code>或<code>r'\\'</code>在Python正则表达式中显示信号<code>\</code>。你知道吗</p>
<p>但是关于这个,从<a href="https://stackoverflow.com/a/4025505">this answer</a>:</p>
<blockquote>
<p>If you're putting this in a string within a program, you may actually need to use four backslashes (because the string parser will remove two of them when "de-escaping" it for the <em>string</em>, and then the regex needs two for an escaped regex backslash).</p>
</blockquote>
<p>和<a href="https://docs.python.org/3/howto/regex.html#the-backslash-plague" rel="nofollow noreferrer">the document</a>:</p>
<blockquote>
<p>As stated earlier, regular expressions use the backslash character (<code>'\'</code>) to indicate special forms or to allow special characters to be used without invoking their special meaning. This conflicts with Python's usage of the same character for the same purpose in string literals.</p>
<p>Let's say you want to write a RE that matches the string <code>\section</code>, which might be found in a LaTeX file. To figure out what to write in the program code, start with the desired string to be matched. Next, you must escape any backslashes and other metacharacters by preceding them with a backslash, resulting in the string <code>\\section</code>. The resulting string that must be passed to <code>re.compile()</code> must be <code>\\section</code>. However, to express this as a Python string literal, both backslashes must be escaped again.</p>
</blockquote>
<hr/>
<p>正如brittenb所建议的,在这种情况下,您不需要RegEx:</p>
<pre><code>>>> x = 'the meaning\nof life'
>>> x.replace("\n", " ")
'the meaning of life'
>>>
</code></pre>