.py file's code:
...
datafile=fields.Binary("File")
...

file_like=io.BytesIO(base64.b64decode(self.datafile))
table=pandas.ExcelFile(file_like)
col_name=table.parse(0).icol(1).real[1:]
col_datetime=table.parse(0).icol(3)[1:]
...

Now I have modified some data of table;

how shall I write the modified data of the "table" back in a "Binary fields" for users to download?