如何用正则表达式合并拆分多行的单行文本并保留独立句子

核心替换规则 #

使用正则匹配非空行末尾的换行符+后续小写字母开头的内容，将其替换为空格连接的形式，同时保留空行和首字母大写的独立句子。

• 正则模式：(?<!\n)\n\s*([a-z])
• 替换字符串： $1

正则逻辑解释 #

• (?<!\n)：负向后断言，确保当前换行符的前一个字符不是换行（排除空行场景，避免合并空行）
• \n：匹配需要处理的换行符
• \s*：匹配换行后可能存在的任意空白字符（空格、制表符等），统一替换为单个空格
• ([a-z])：捕获下一行开头的小写字母，替换时保留该字母，保证文本连贯性

代码示例（Python） #

import re

original_str = '''I love to eat apple and 
bananas but at the same time, I do
not like to eat oranges 
and I am not a fan of vegetables.

I also like to eat biscuits.
I also like to eat crackers.

Meanwhile, oddly enough, I have never liked
ice creams or chocolates because I
am never a sweet-toothed.'''

# 执行替换
new_str = re.sub(r'(?<!\n)\n\s*([a-z])', r' \1', original_str)

print(new_str)

输出结果 #

I love to eat apple and bananas but at the same time, I do not like to eat oranges  and I am not a fan of vegetables.

I also like to eat biscuits.
I also like to eat crackers.

Meanwhile, oddly enough, I have never liked ice creams or chocolates because I am never a sweet-toothed.

内容的提问来源于stack exchange，提问作者Noor Ameera Anas