Python - catching "kill" signal, sending "kill" signal

############################################################################
# script.py
# It has signal's handler so it can close connections/files at the end.
# It saves its PID in file so admin can use it to send signal to this script
############################################################################

import signal
import time
import os

def exit_gracefully(signum, frame):
    print("closing connections/files ...")

    # closing ... longer time
    time.sleep(3)

    print("end of the program.")
    exit()
    #exit(1) # exit with some code

#---------------------------------------------------------------------------

# register signals
signal.signal(signal.SIGINT, exit_gracefully)
signal.signal(signal.SIGTERM, exit_gracefully)

# save PID in file so admin can use it to kill this script
pid = os.getpid()
with open('script.lock', 'w') as out:
    out.write(str(pid))

# long runnig program
while True:
    print("simulate long running program ...")
    time.sleep(1)

############################################################################
# admin.py
# It gets script's PID from file and sends signal to close this script
############################################################################

import signal
import os

with open('script.lock') as f:
    pid = int(f.read())
os.kill(pid, signal.SIGTERM)