Error: ('IM002', '[IM002] [unixODBC][Driver Manager]Data source name not found, and no default driver specified (0) (SQLDriverConnect)')

import pyodbc

def createdatabase():
    driver = 'SQL Server'
    server = '00000000'
    db1 = 'Vodafone'
    tcon = 'yes'
    uname = 'user'
    pword = 'pwd'

    cnxn = pyodbc.connect(driver='{SQL Server}', host=server,database=db1,trusted_connection=tcon, user=uname, password=pword)
    cursor = cnxn.cursor()

DRIVER={FreeTDS};SERVER=yoursqlserver.com;PORT=1433;DATABASE=yourdb;UID=youruser;PWD=yourpass;TDS_Version=7.2;