class loadFiles(object):
    def __init__(self,par_path):
        self.par_path = par_path
    def __iter__(self):
        folders = loadFolders(self.par_path)
        for folder in folders:                     # 1 level directory
            catg = folder.split(os.sep)[-1] #sep是用来分隔分隔符的
            for file in os.listdir(folder):        # secondary directory
                file_path = os.path.join(folder,file)
                # 读取文本的具体操作
                if os.path.isfile(file_path):
                    this_file = open(file_path,'rb') # rb（二进制）读取更快
                    content = this_file.read().decode('utf-8')
                # print(catg,file)