python 获取文件夹下所有文件包含子目录文件

    def get_all_files(dir):
        files_ = []
        list = os.listdir(dir)
        for i in range(0, len(list)):
            path = os.path.join(dir, list[i])
            if os.path.isdir(path):
                files_.extend(get_all_files(path))
            if os.path.isfile(path):
                files_.append(path)
        return files_
    def get_all_files(dir):
        files_