使用r将字符串中的匹配单词替换为单词

import re

def replace_word(string, word, replacement):
    pattern = r'\b' + word + r'\b'
    replaced_string = re.sub(pattern, replacement, string)
    return replaced_string

# 示例用法
string = "This is a sample string. Sample is the keyword."
word = "Sample"
replacement = "Replacement"
replaced_string = replace_word(string, word, replacement)
print(replaced_string)

This is a sample string. Replacement is the keyword.

replaced_string = re.sub(pattern, replacement, string, flags=re.IGNORECASE)