Python regex - 删除标点符号但保留 原样

Question

题
请建议一种去除标点符号的方法，但不是<unk> 中的那些。或 <UNK> .
例如，来自:the asbestos fiber <unk> <unk| is < unusually <unk once it enters the <<unk>$% with 产生:the asbestos fiber <unk> unk is unusually unk once it enters the unk with 在下面尝试过，但没有达到预期。

text = "the asbestos fiber <unk> <unk| is < unusually <unk once it enters the <<unk>$% with "

replacement = " "
pattern: str = '(?<!<unk)[%s%s]+(?!unk>)' % (re.escape(string.punctuation), r"\s")

re.sub(pattern=pattern, repl=replacement, string=text, flags=re.IGNORECASE).lower().strip()

结果: the asbestos fiber <unk> unk| is unusually unk once it enters the <unk> with

Answer 1

您可以使用以下正则表达式搜索匹配项并将其替换为空格:

(?:(?!<unk>)[\W_](?<!<unk>))+

见 regex demo .
细节:

(?: - 非捕获组的开始:

(?!<unk>) - 下一个字符不应该是 <unk> 的起始字符字符序列

[\W_] - 任何非字母数字字符

(?<!<unk>) - 先前匹配的字符(带有 [\W_] )不能是 <unk> 的起始字符字符序列

)+ - 一次或多次。

见 Python demo :

import re
text = "the asbestos fiber <unk> <unk| is < unusually <unk once it enters the <<unk>$% with "
replacement = " "
pattern: str = r'(?:(?!<unk>)[\W_](?<!<unk>))+'
print( re.sub(pattern, replacement, text, flags=re.I) )
# => the asbestos fiber <unk> unk is unusually unk once it enters the <unk> with