提取字节文本文件中两个字符之间的字符串

import re

def extract_string(filename, char1, char2):
    with open(filename, 'rb') as file:
        content = file.read().decode('utf-8')  # 以utf-8编码读取文件内容，转为字符串

    pattern = re.escape(char1) + '(.*?)' + re.escape(char2)  # 构造正则表达式模式
    result = re.search(pattern, content)  # 进行匹配

    if result:
        extracted_string = result.group(1)  # 获取匹配到的字符串
        return extracted_string
    else:
        return "No matching string found."

# 示例用法
filename = 'file.txt'
char1 = '{'
char2 = '}'
extracted_string = extract_string(filename, char1, char2)
print(extracted_string)