无法通过覆盆子pi中的php运行python脚本

I have the following piece of code:

echo $k;                    
if ($k==9)

{$sql = "SELECT EventName,ACName,username FROM acslots WHERE slot".$i." ='9'";
$result = $con->query($sql);

if ($result->num_rows > 0) {
     // output data of each row
     while($row = $result->fetch_assoc()) {
         echo "<br> To aircondition  ". $row["ACName"]. " leitourgei gia ton xrhsth  ". $row["username"]. " gia to event " . $row["EventName"] . "<br>";
     }}

    $command = escapeshellcmd("usr/bin/python /var/www/family_guy/codecall/openACled.py");
$output = shell_exec($command);
echo $output;



    }

else {##apenergopoihsh led
$command = escapeshellcmd('usr/bin/python /var/www/family_guy/codecall/closeAcled.py');
$output = shell_exec($command);
echo $output;}

?> Let's say $k right now is 9. /var/www/family_guy/codecall/openACled.py is supposed to open a LED, however it doesn't work. I find that permissions in /var/www/family_guy/codecall/openACled.py are -rwsrwxr-x by using ls-ltr.Please help me.