如何使用Python在不添加新行的情况下更改循环内文件中的行值？

def modify_file(filename, target_line, new_value):
    with open(filename, 'r') as file:
        lines = file.readlines()

    with open(filename, 'w') as file:
        for i, line in enumerate(lines):
            if i == target_line:
                # 修改目标行的值
                modified_line = line.replace(line.strip(), new_value)
                file.write(modified_line)
            else:
                file.write(line)

modify_file('example.txt', 2, 'New Value')