Ping an IP and log its availability

ping.py

import datetime
import os
import platform
import sys
import threading


def how_to_use():
    print("Usage: python3 ping.py [ip adress] [log|csv] [interval]\n")
    print("\tip adress = server adress to ping\n")
    print("\tlog = save to log file")
    print("\tcsv = save to csv file\n")
    print("\tinterval = logging interval in seconds")
    exit()


def get_command(ip):
    operating_system = platform.system()
    if (operating_system == "Windows"):
        command = f"ping {ip} -n 1 | echo Pinging {ip}"
    else:
        command = f"ping {ip} -c 1 2>&1 >/dev/null | echo Pinging {ip}"

    return command


def ping(ip, command, output):
    timestamp = datetime.datetime.now()
    available = "available" if os.system(command) == 0 else "unavailable"
    log_output = f"{timestamp}: Server {ip} {available}\n"
    csv_output = f"{timestamp},{ip},{available}\n"
    if str.lower(output) == "log":
        return log_output
    if str.lower(output) == "csv":
        return csv_output


def write_to_file(ip, result, output):
    if output == "log":
        filename = f"{ip}.log"
    elif output == "csv":
        filename = f"{ip}.csv"

    if (os.path.exists(filename)):
        append_write = "a"
    else:
        append_write = "w"

    f = open(filename, append_write)
    f.write(result)
    f.close()


def monitor():
    interval = float(sys.argv[3])
    threading.Timer(interval, monitor).start()

    ip = sys.argv[1]
    output = sys.argv[2]
    command = get_command(ip)
    result = ping(ip, command, output)
    write_to_file(ip, result, output)


if len(sys.argv) is not 4:
    print("Invalid Argument length\n")
    how_to_use()

if (sys.argv[2] != "csv" and sys.argv[2] != "log"):
    print("Invalid file extension")
    print("Argument must either be 'csv' or 'log'\n")
    how_to_use()

if not sys.argv[3].isdigit():
    print("Invalid interval")
    print("Argument is not a number\n")
    how_to_use()

monitor()