Not able to convert blob file to its original excel file from the database

I am using below script to fetch and convert the blob file stored in IBM db2 database using jupyter notebook. The blob file stored in database is in excel format. I am trying from last few days and I am able to fetch and convert the file in excel into my hard disk but when I open that excel the data I am getting is in binary format. I want the excel as it was when stored. Can anyone help me in this.

import ibm_db
import ibm_db_dbi

connection = ibm_db.connect("DATABASE; HOSTNAME; PORT; PROTOCOL; UID; PWD;","","")
conn = ibm_db_dbi.Connection(connection)
cur = conn.cursor()

def write_file(data, filename):
    with open(filename, 'wb') as file:
        file.write(data)
def readBLOB(ID,DATA): # data column is in blob data type
    query = "SELECT DATA FROM FILEDATA WHERE ID= '12345'"
    cur.execute(query,(ID,))
    record = cur.fetchone()[0]
    write_file(file, 'User'+'.xls')

readBLOB(1,"D:\\New folder\\User.xls")

On this line:

write_file(file, 'User'+'.xls')

what is file?