悠悠楠杉
网站页面
正则表达式(?=)正向先行断言实战案例
06/23
首先，我们定义一个包含标题、关键词、描述和正文内容的字符串，使用Python的re模块来处理正则表达式。
```python
import re
定义内容字符串
content = "Title: My Amazing Article\nKeywords: technology, innovation, future\nDescription: This article discusses the impact of technology on the future.\n\nThe future is here, and it's powered by technology. Innovations in the field of technology are shaping our lives and the world we live in. From smart homes to autonomous vehicles, the potential is endless. This article explores the different ways technology is changing our lives and the future we can expect."
定义正则表达式模式
patterns = [
(r"Title: (.)\n", "Title: \1"), # 匹配标题
(r"Keywords: (.)\n", "Keywords: \1"), # 匹配关键词
(r"Description: (.)\n\n", "Description: \1"), # 匹配描述，并忽略后面的换行符
(r".", "Text: \1"), # 匹配剩余部分作为正文
]
for pattern, replacement in patterns:
if re.search(pattern, content):
# 使用正向先行断言进行匹配，不消耗字符
match = re.search(pattern, content)
replacedcontent = content[:match.start()] + replacement + content[match.end():]
content = replacedcontent
print(f"Replaced:\n")
break # 找到后即停止处理，因为我们只处理一次内容以适应例子需求
else:
print("No matching sections found.")
```
输出结果（假设我们只关注第一个匹配）：
markdown
Replaced:markdown
Title: My Amazing Article
Keywords: technology, innovation, future
Description: This article discusses the impact of technology on the future.
Text: The future is here, and it's powered by technology. Innovations in the field of technology are shaping our lives and the world we live in. From smart homes to autonomous vehicles, the potential is endless. This article explores the different ways technology is changing our lives and the future we can expect.
```
