from flask import send_file
from xlsxwriter import Workbook
@app.route('/download', methods=['GET'])
def export_db():
values = execute("SELECT * from table",[])
wb = Workbook('path/to/workbook.xlsx')
wb.add_worksheet('All Data')
for item in values.fetchall():
wb.write(item)
wb.close()
return send_file('path/to/workbook.xlsx')