如何在使用Python的Unicode编码的*.txt文件中查找和替换字符串？

# 打开文件并读取内容
with open('example.txt', 'r', encoding='utf-8') as file:
    content = file.read()

# 查找和替换字符串
old_string = 'old_text'
new_string = 'new_text'
modified_content = content.replace(old_string, new_string)

# 将修改后的内容写回文件
with open('example.txt', 'w', encoding='utf-8') as file:
    file.write(modified_content)

import re

# 打开文件并读取内容
with open('example.txt', 'r', encoding='utf-8') as file:
    content = file.read()

# 使用正则表达式查找和替换字符串
pattern = re.compile(r'old_text_pattern')  # 使用正则表达式模式
modified_content = pattern.sub('new_text', content)

# 将修改后的内容写回文件
with open('example.txt', 'w', encoding='utf-8') as file:
    file.write(modified_content)