This is a Python script to do some country code math when I was working with book metadata. It seemed that Amazon didn't recognize the newer country codes so they have an exception case. This was helpful in case someone expressed their sales rights as "Nowhere but US", but I needed to express it as "US only" (invert the expression).

country-math.py

#!/bin/python
import argparse
# Usage: country-math.py -a "US CA SS EY"
# Usage: country-math.py "US CA SS EY" -o "US CA SS EY GB"

parser = argparse.ArgumentParser(description="Intersect two ISO country code lists. Remove countries found in REMOVE_COUNTRIES from ORIGINAL_COUNTRIES or the world.")
parser.add_argument("countries", help="List of undelimited country codes surrounded by doublequotes that need to be removed", metavar="REMOVE_COUNTRIES")
parser.add_argument("-a", "--amazon", help="Remove country codes that are not supported by Amazon.", action='store_true')
parser.add_argument("-o", "--originallist", dest="originalcountries", help="List of undelimited country codes that represent original list. This list needs to be surrounded by doublequotes. If this flag is not provided, then program will default to all country codes", metavar="ORIGINAL_COUNTRIES")
parser.set_defaults(amazon=False)

AllCountries =  [ "AD", "AE", "AF", "AG", "AI", "AL", "AM", "AO", "AQ", "AR", "AS", "AT", "AU", "AW", "AX", "AZ", "BA", "BB", "BD", "BE", "BF", "BG", "BH", "BI", "BJ", "BL", "BM", "BN", "BO", "BQ", "BR", "BS", "BT", "BV", "BW", "BY", "BZ", "CA", "CC", "CD", "CF", "CG", "CH", "CI", "CK", "CL", "CM", "CN", "CO", "CR", "CS", "CU", "CV", "CW", "CX", "CY", "CZ", "DE", "DJ", "DK", "DM", "DO", "DZ", "EC", "EE", "EG", "EH", "ER", "ES", "ET", "FI", "FJ", "FK", "FM", "FO", "FR", "GA", "GB", "GD", "GE", "GF", "GG", "GH", "GI", "GL", "GM", "GN", "GP", "GQ", "GR", "GS", "GT", "GU", "GW", "GY", "HK", "HM", "HN", "HR", "HT", "HU", "ID", "IE", "IL", "IM", "IN", "IO", "IQ", "IR", "IS", "IT", "JE", "JM", "JO", "JP", "KE", "KG", "KH", "KI", "KM", "KN", "KP", "KR", "KW", "KY", "KZ", "LA", "LB", "LC", "LI", "LK", "LR", "LS", "LT", "LU", "LV", "LY", "MA", "MC", "MD", "ME", "MF", "MG", "MH", "MK", "ML", "MM", "MN", "MO", "MP", "MQ", "MR", "MS", "MT", "MU", "MV", "MW", "MX", "MY", "MZ", "NA", "NC", "NE", "NF", "NG", "NI", "NL", "NO", "NP", "NR", "NU", "NZ", "OM", "PA", "PE", "PF", "PG", "PH", "PK", "PL", "PM", "PN", "PR", "PS", "PT", "PW", "PY", "QA", "RE", "RO", "RS", "RU", "RW", "SA", "SB", "SC", "SD", "SE", "SG", "SH", "SI", "SJ", "SK", "SL", "SM", "SN", "SO", "SR", "SS", "ST", "SV", "SX", "SY", "SZ", "TC", "TD", "TF", "TG", "TH", "TJ", "TK", "TL", "TM", "TN", "TO", "TR", "TT", "TV", "TW", "TZ", "UA", "UG", "UM", "US", "UY", "UZ", "VA", "VC", "VE", "VG", "VI", "VN", "VU", "WF", "WS", "YE", "YT", "YU", "ZA", "ZM", "ZW" ]

UnsupportedAMZ = [ "BQ", "CS", "CW", "SS", "SX", "YU" ]

def main():
    args = parser.parse_args()
    removecountries = args.countries.replace(",","").replace(";","").split(" ")
    if args.originalcountries:
        countries = args.originalcountries.replace(",","").replace(";","").split(" ")
    else:
        countries = AllCountries
    
    
    # Validate given country codes
    for x in removecountries:
        if x not in AllCountries:
            print "%s is not a valid Country Code. Removed from list." % x
            removecountries.remove(x)
    for x in countries:
        if x not in AllCountries:
            print "%s is not a valid Country Code. Removed from list." % x
            countries.remove(x)
    
    
    # Return intersection
    if args.amazon:
        removecountries = removecountries + UnsupportedAMZ
    finalcountries = [x for x in countries if x not in removecountries]
    removedcountries = [x for x in countries if x in removecountries]

    print " "
    print "Final List:"
    print " ".join(finalcountries)
    print " "
    print "Countries identified that were removed from final list:"
    print " ".join(removedcountries)

if __name__ == "__main__":
    main()