I'm not sure about how to properly handle timing readings from serial inside a Python script. I need to read a value every 5 seconds.

From Arduino I could do,

Serial.println(value);
delay(5000); // should I wait here?

Inside Python script I could do,

import serial
import time

arduino = serial.Serial('/dev/ttyACM1', 9600, timeout=5) # should I set timeout?

while True and arduino.isOpen():
    
    try:    
        value = arduino.readline().strip()
        print value

        time.sleep(5) # should I wait here?

    except KeyboardInterrupt:
        print "\nClosing..."
        arduino.close() 

EDIT: Apart from that, the first reading is always wrong, like if there was something in the reading buffer. I've found out that to solve that I should add arduino.flushInput() just after opening the port.