如何在python中合并文本文件中的某些行

def merge_lines(input_file, output_file, merge_condition):
    lines_to_merge = []
    
    # 打开要合并的文本文件
    with open(input_file, 'r') as file:
        # 遍历文件的每一行
        for line in file:
            # 判断是否满足合并条件
            if merge_condition(line):
                lines_to_merge.append(line)
    
    # 打开要写入的目标文件
    with open(output_file, 'w') as file:
        # 将列表中的行写入目标文件
        file.writelines(lines_to_merge)

# 示例用法：合并包含关键字"merge"的行
merge_lines('input.txt', 'output.txt', lambda line: 'merge' in line)