如何在python中使用regex用正则表达式模式替换子字符串？

import re

# 原始字符串
text = "The quick brown fox jumps over the lazy dog."

# 正则表达式模式
pattern = r"fox"

# 替换字符串
replacement = "cat"

# 使用re.sub()函数进行替换
result = re.sub(pattern, replacement, text)

print(result)

The quick brown cat jumps over the lazy dog.

result = re.sub(pattern, replacement, text, count=1)

import re

text = "John Doe's email is john.doe@example.com and Jane Smith's email is jane.smith@example.com."

# 匹配电子邮件地址的正则表达式模式
pattern = r"(\w+)\.(\w+)@example\.com"

# 替换字符串，使用\1和\2引用捕获的分组
replacement = r"\1.\2@newdomain.com"

result = re.sub(pattern, replacement, text)

print(result)

John Doe's email is john.doe@newdomain.com and Jane Smith's URL is jane.smith@newdomain.com.