#!/usr/bin/python
import RPi.GPIO as GPIO
import time
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(22, GPIO.OUT)
while True:
    GPIO.output(22, True)
    time.sleep(1)
    GPIO.output(22, False)
    time.sleep(1)

sudo apt-get install lirc

sudo nano /etc/modules

lirc_dev
lirc_rpi gpio_out_pin=22

gpio_out_pin parameter points to the pin controlling the IR LED

LIRCD_ARGS="--uinput"
LOAD_MODULES=true
DRIVER="default"
DEVICE="/dev/lirc0"
MODULES="lirc_rpi"
LIRCD_CONF=""
LIRCMD_CONF=""

dtoverlay=gpio-ir,gpio_pin=18
dtoverlay=gpio-ir-tx,gpio_pin=22

driver          = default 
device          = /dev/lirc0

sudo reboot