Issue with read and writing serialy (python 3 with ubuntu)

It would be amazing ig your could provide some sample code for the long and Int transfer. I am currently having some issues.
Here is some of my code if you wouldn't mind going through it. The issue I am getting is that it hangs at the first loop (seeing if the arduino is ready after it resets from opening a serial port) The arduino does reset but nothing on either side does anything after that. I know this because of a couple print statements (not connected to the serial besides the loop they are in) i didn't include never show up

Python

class Target:
def run():
    (code not important (from openCV library)
    ser = serial.Serial("/dev/ttyACM0", 57600)
    connected = 0
    while connected == 0: //From consoul messages I am guessing this is where it is getting hung
        ser.write("3")               // I am little confused because the pySerial will only send strings but the arduino will not read strings?
        if ser.read() == 4:      //Might be the reason why the "connected" variable will never switch and end the loop
            connected = 1
        time.sleep(1) 
    while connected == 1:
    (a lot of code related to openCV and not arduino serial)
    ser.write("1") # cheacking to see if the arduino is ready for now command
    read = ser.read()
    if read == 2:  #the value two is the arduino saying it is ready for a new command 
        ser.write(str(center_point[1])) # Part of openCV code that needs to be sent to arduino
        time.sleep(.1) #giving arduino time to move value out of serial cache and into array(just thought of that now not really sure how to implement that into arduino code)
       ser.write(center_point[2]))

Arduino

int readSerial = 0;

void setup() {
  pinMode(5, OUTPUT);
  Serial.begin(9600);
}
void loop() {
  readSerial = Serial.parseInt();
  if (readSerial == 3) {
    Serial.write(4);
    readSerial = Serial.parseInt();
    if (readSerial == 2) {
      Serial.write(3);
      readSerial = Serial.parseInt();
      Serial.print(readSerial);
    }
  }

}

You did not post your Arduino code - just 2 copies of the Python code.

Look at this demo and this demo.

I’m not sure which problem you are trying to solve.

…R