Read the excel files, concat them and append the data − for file in filenames: df = pd.concat (pd.read_excel (file, sheet_name=None), ignore_index=True, sort=False) outputxlsx = outputxlsx.append (df, ...

filename@n () represents obtaining the file names in the A1 path, such as Fruits, Meats derive () means adding a derived variable "Category" to each table opened by the T () function, with the value ...