some help with reading line from CMD on PI

[korenron]

this is what I'm tryting now

but I'm having problems
can you take a look , please?

import pexpect
import datetime
import time
child = pexpect.spawn("bluetoothctl")
child.send("scan on\n")
SendToServer = []

try:
    print("Scan Begin")
    while True:
        now = datetime.datetime.now()
        future = (now+ 10) #####--->this is not wroking##### 
        child.expect("Device (([0-9A-Fa-f]{2}:){5}([0-9A-Fa-f]{2})) RSSI: (-[0-9]{2})",timeout=None)
        bdaddr = child.match.group(1)
        bdrssi = child.match.group(4)
        DeviceInfo = ((bdaddr + b'!' + bdrssi))
        print(DeviceInfo)
        SendToServer.append(DeviceInfo)
        if now>future:#### --->this is also not working also obvious :-) #### 
            print("it's been 10 seconds" + now)
            ##cdoe for sending to server, need to write 
            print ("Old size is - " + len(SendToServer))
            SendToServer.clear()
            print ("Ne size need to be 0" + len(SendToServer))
            break    
                
except KeyboardInterrupt:
    child.close()

and also what do you mean be set()?

Thanks,