我需要写一个正则表达式来替换'.' with ','在一些患者对药物的评论中。他们应该在提到副作用后使用逗号，但其中一些使用了点。例如：

text = "the drug side-effects are: night mare. nausea. night sweat. bad dream. dizziness. severe headache.  I suffered. she suffered. she told I should change it."

我编写了一个正则表达式代码来检测由两个点包围的一个单词（例如，头痛）或两个单词（例如，噩梦）：

检测由两个点包围的单词：

text=  re.sub (r'(\.)(\s*\w+\s*\.)',r',\2 ', text )

检测由两个点包围的两个单词：

text =  re.sub (r'(\.)(\s*\w+\s\w+\s*\.)',r',\2 ', text11 )

这是输出：

the drug side-effects are: night mare, nausea,  night sweat.  bad dream, dizziness,  severe headache.   I suffered, she suffered.  she told I should change it.

但应该是：

the drug side-effects are: night mare, nausea,  night sweat,  bad dream, dizziness,  severe headache.   I suffered. she suffered.  she told I should change it.

我的代码没有替换dot after night sweat to ','。我补充说，if a sentence starts with a subject pronoun (such as I and she) I do not want to change dot to comma after it, even if it has two words (such as, I suffered)。我不知道如何将此条件添加到我的代码中。

有什么建议吗？谢谢 ！

您可以使用以下模式：

\.(\s*(?!(?:i|she)\b)\w+(?:\s+\w+)?\s*)(?=[^\w\s]|$)

这匹配一个点，然后捕获一个或两个单词，其中第一个单词不是您提到的代词（您很可能需要扩展该列表）。后面必须跟一个既不是单词字符也不是空格的字符（例如. ! : ,) 或字符串的末尾。

然后你必须将其替换为,\1

在Python中

import re
text = "the drug side-effects are: night mare. nausea. night sweat. bad dream. dizziness. severe headache.  I suffered. she suffered. she told I should change it."
text = re.sub(r'\.(\s*(?!(?:i|she)\b)\w+(?:\s+\w+)?\s*)(?=[^\w\s]|$)', r',\1', text, flags=re.I)
print(text)

Outputs

the drug side-effects are: night mare, nausea, night sweat, bad dream, dizziness, severe headache.  I suffered. she suffered. she told I should change it.

这可能不是绝对安全的，您可能必须针对某些边缘情况扩展模式。