Mysql Database query error in python -

my database cannot query. when run code it's show me error .

def button_click(self):     # shost qstring object     shost = self.le.text()     if shost:         s_h = "127.0.0.1"        s_n = "root"        s_p = ""        s_d = "code"         s_cn = mdb.connect(s_h, s_n, s_p, s_d)         cursor = s_cn.cursor()        today = datetime.date.today()        mac = get_mac()        query = "insert `ac` (`acc`, `mac`, `date`) values (%s, %s, %s)"        re = cursor.execute(query,(shost,mac,today,))                   if re:             self.ex = example()            self.ex.show()         else:           query1 = "select *  `ac`  `acc` = %s,`mac` = $s"           ck = cursor.execute(query1,(shost,mac))           if(ck):              self.ex = example()              self.ex.show()           else:               print 'no'   

i want know how write sql code python variable how can fix ?

  query = "insert `ac` (`acc`, `mac`, `date`) values (%s, %s, %s)"    re = cursor.execute(query,(shost,mac,today,)) 

and

          query1 = "select *  `ac`  `acc` = %s,`mac` = $s"           ck = cursor.execute(query1,(shost,mac)) 

query1 = "select * fromacwhereacc= %s,mac= $s"

$s - not valid placeholder, replace %s.