替换文件中的模式实例

import os

def replace_string_in_file(file_path, old_string, new_string):
    with open(file_path, 'r') as file:
        file_data = file.read()

    file_data = file_data.replace(old_string, new_string)

    with open(file_path, 'w') as file:
        file.write(file_data)

# 示例用法
file_path = 'example.txt'
old_string = 'old_text'
new_string = 'new_text'
replace_string_in_file(file_path, old_string, new_string)

import re
import os

def replace_regex_in_file(file_path, pattern, replacement):
    with open(file_path, 'r') as file:
        file_data = file.read()

    file_data = re.sub(pattern, replacement, file_data)

    with open(file_path, 'w') as file:
        file.write(file_data)

# 示例用法
file_path = 'example.txt'
pattern = r'foo\d+'  # 匹配 'foo' 后跟一个或多个数字
replacement = 'bar'
replace_regex_in_file(file_path, pattern, replacement)