Python IP geolocator

geoip.py

# Small python program to retrieve location and/or
# other infos about a internet address.
# Requires python3 and requests library.
# Thanks to freegeoip.net for its free JSON API.

import requests
import sys

GEOIP_URL = "http://freegeoip.net/json/"
arg_options = []
arg_hostname = ""

def geoip_json(hostname = ""):
    global GEOIP_URL
    try:
        req = requests.get(GEOIP_URL + hostname)
        return req.json()
    except Exception as err:
        print("ERROR: Cannot retrieve data from server " + GEOIP_URL, file=sys.stderr)
        print(err, file=sys.stderr)
        sys.exit(1)

def print_help(options = ""):
    print(  "Usage: geoip [hostname] [options...]\n"
            "    hostname: Address to locate (your address if not specified)\n"
            "Special options:\n"
            "    -help:     Shows this help\n"
            "    -raw:      Outputs raw JSON data\n"
            "Other available options:")
    for name in options:
        print("    -" + name)
    
# Check valid options
for arg in sys.argv[1:]:
    if arg[0] == '-':
        arg_options.append(arg[1:])
    elif not arg_hostname:
        arg_hostname = arg
    else:
        print("ERROR: Only one hostname is allowed ", file=sys.stderr)
        sys.exit(1)

# Request from server
json_res = geoip_json(arg_hostname)


if arg_options.count("help"):
    print_help(json_res)
elif arg_options.count("raw"):
    print(json_res)
elif len(arg_options) > 0:
    # Print each value on a different line
    for arg in arg_options:
        # Show value only if that field exists
        if arg in json_res:
            print(json_res[arg])
else:
    # Print only important information
    fmt = "Host: {}\nLocation: {}\nCountry: {}\nCoords: {}, {}"
    print(fmt.format(
        json_res["ip"],
        json_res["city"] + ", " + json_res["region_name"] if json_res["city"] else json_res["region_name"],
        json_res["country_name"], 
        json_res["latitude"],
        json_res["longitude"]))