import pymysql.cursors
def adapter(kurseuro):
	cena_adapter = 399*kurseuro
	db = pymysql.connect(host='host',
                             user='user',
                             password='password',                             
                             db='db')
	sql = ("UPDATE wp_postmeta SET meta_value = '%s' WHERE wp_postmeta.meta_id = 1310" % (cena_adapter))
	cursor.execute(sql)
	db.commit()
	db.close()
	
if __name__ == "__main__":       
	adapter(31)