Country names harvested from the "countries" Ruby gem (https://github.com/hexorx/countries)

collect_countries.rb

require 'countries'
require 'json'
require 'active_support'
require 'sort_alphabetical'

lang = ARGV[0] || 'cs'

data = ISO3166::Country
       .all
       .collect {|c| {name: c.translations[lang], code: c.alpha2} }
       .reject {|c| c[:name].nil? }
       .sort_alphabetical_by {|c| c[:name] }
puts JSON.dump data

countries.cz.json

[{"name":"Afghánistán","code":"AF"},{"name":"Ålandské ostrovy","code":"AX"},{"name":"Albánie","code":"AL"},{"name":"Alžírsko","code":"DZ"},{"name":"Americká Samoa","code":"AS"},{"name":"Andorra","code":"AD"},{"name":"Angola","code":"AO"},{"name":"Anguilla","code":"AI"},{"name":"Antarktida","code":"AQ"},{"name":"Antigua a Barbuda","code":"AG"},{"name":"Argentina","code":"AR"},{"name":"Arménie","code":"AM"},{"name":"Aruba","code":"AW"},{"name":"Austrálie","code":"AU"},{"name":"Ázerbájdžán","code":"AZ"},{"name":"Bahamy","code":"BS"},{"name":"Bahrajn","code":"BH"},{"name":"Bangladéš","code":"BD"},{"name":"Barbados","code":"BB"},{"name":"Belgie","code":"BE"},{"name":"Belize","code":"BZ"},{"name":"Bělorusko","code":"BY"},{"name":"Benin","code":"BJ"},{"name":"Bermudy","code":"BM"},{"name":"Bhútán","code":"BT"},{"name":"Bolívarovská republika Venezuela","code":"VE"},{"name":"Bonaire, Svatý Eustach a Saba","code":"BQ"},{"name":"Bosna a Hercegovina","code":"BA"},{"name":"Botswana","code":"BW"},{"name":"Bouvetův ostrov","code":"BV"},{"name":"Brazílie","code":"BR"},{"name":"Britské indickooceánské území","code":"IO"},{"name":"Brunej","code":"BN"},{"name":"Bulharsko","code":"BG"},{"name":"Burkina Faso","code":"BF"},{"name":"Burundi","code":"BI"},{"name":"Čad","code":"TD"},{"name":"Černá Hora","code":"ME"},{"name":"Česká republika","code":"CZ"},{"name":"Chile","code":"CL"},{"name":"Chorvatsko","code":"HR"},{"name":"Čína","code":"CN"},{"name":"Cookovy ostrovy","code":"CK"},{"name":"Curaçao","code":"CW"},{"name":"Dánsko","code":"DK"},{"name":"Dominika","code":"DM"},{"name":"Dominikánská republika","code":"DO"},{"name":"Džibutsko","code":"DJ"},{"name":"Egypt","code":"EG"},{"name":"Ekvádor","code":"EC"},{"name":"Eritrea","code":"ER"},{"name":"Estonsko","code":"EE"},{"name":"Etiopie","code":"ET"},{"name":"Faerské ostrovy","code":"FO"},{"name":"Falkandské ostrovy (Malvíny)","code":"FK"},{"name":"Fidži","code":"FJ"},{"name":"Filipíny","code":"PH"},{"name":"Finsko","code":"FI"},{"name":"Francie","code":"FR"},{"name":"Francouzská Guayana","code":"GF"},{"name":"Francouzská Polynésie","code":"PF"},{"name":"Francouzská jižní území","code":"TF"},{"name":"Gabon","code":"GA"},{"name":"Gambie","code":"GM"},{"name":"Ghana","code":"GH"},{"name":"Gibraltar","code":"GI"},{"name":"Grenada","code":"GD"},{"name":"Grónsko","code":"GL"},{"name":"Gruzie","code":"GE"},{"name":"Guadeloupe","code":"GP"},{"name":"Guam","code":"GU"},{"name":"Guatemala","code":"GT"},{"name":"Guernsey","code":"GG"},{"name":"Guinea","code":"GN"},{"name":"Guinea-Bissau","code":"GW"},{"name":"Guyana","code":"GY"},{"name":"Haiti","code":"HT"},{"name":"Heardův a McDonaldovy ostrovy","code":"HM"},{"name":"Honduras","code":"HN"},{"name":"Hongkong","code":"HK"},{"name":"Indie","code":"IN"},{"name":"Indonésie","code":"ID"},{"name":"Irák","code":"IQ"},{"name":"Írán, islámská republika","code":"IR"},{"name":"Irsko","code":"IE"},{"name":"Island","code":"IS"},{"name":"Itálie","code":"IT"},{"name":"Izrael","code":"IL"},{"name":"Jamajka","code":"JM"},{"name":"Japonsko","code":"JP"},{"name":"Jemen","code":"YE"},{"name":"Jersey","code":"JE"},{"name":"Jihoafrická republika","code":"ZA"},{"name":"Jižní Georgie a Jižní Sandwichovy ostrovy","code":"GS"},{"name":"Jižní Súdán","code":"SS"},{"name":"Jordánsko","code":"JO"},{"name":"Kajmanské ostrovy","code":"KY"},{"name":"Kambodža","code":"KH"},{"name":"Kamerun","code":"CM"},{"name":"Kanada","code":"CA"},{"name":"Kapverdské ostrovy","code":"CV"},{"name":"Katar","code":"QA"},{"name":"Kazachstán","code":"KZ"},{"name":"Keňa","code":"KE"},{"name":"Kiribati","code":"KI"},{"name":"Kokosové ostrovy","code":"CC"},{"name":"Kolumbie","code":"CO"},{"name":"Komory","code":"KM"},{"name":"Kongo","code":"CG"},{"name":"Konžská demokratická republika","code":"CD"},{"name":"Korea, lidově demokratická republika","code":"KP"},{"name":"Korea, republika","code":"KR"},{"name":"Kostarika","code":"CR"},{"name":"Kuba","code":"CU"},{"name":"Kuvajt","code":"KW"},{"name":"Kypr","code":"CY"},{"name":"Kyrgyzstán","code":"KG"},{"name":"Laoská lidově demokratická republika","code":"LA"},{"name":"Lesotho","code":"LS"},{"name":"Libanon","code":"LB"},{"name":"Libérie","code":"LR"},{"name":"Libye","code":"LY"},{"name":"Lichtenštejnsko","code":"LI"},{"name":"Litva","code":"LT"},{"name":"Lotyšsko","code":"LV"},{"name":"Lucembursko","code":"LU"},{"name":"Macao","code":"MO"},{"name":"Madagaskar","code":"MG"},{"name":"Maďarsko","code":"HU"},{"name":"Makedonie, republika","code":"MK"},{"name":"Malajsie","code":"MY"},{"name":"Malawi","code":"MW"},{"name":"Maledivy","code":"MV"},{"name":"Mali","code":"ML"},{"name":"Malta","code":"MT"},{"name":"Maroko","code":"MA"},{"name":"Marshallovy ostrovy","code":"MH"},{"name":"Martinik","code":"MQ"},{"name":"Mauricius","code":"MU"},{"name":"Mauritánie","code":"MR"},{"name":"Mayotte","code":"YT"},{"name":"Menší odlehlé ostrovy Spojených států","code":"UM"},{"name":"Mexiko","code":"MX"},{"name":"Mikronésie, federativní státy","code":"FM"},{"name":"Mnohonárodní stát Bolívie","code":"BO"},{"name":"Moldavská republika","code":"MD"},{"name":"Monako","code":"MC"},{"name":"Mongolsko","code":"MN"},{"name":"Montserrat","code":"MS"},{"name":"Mosambik","code":"MZ"},{"name":"Myanmar","code":"MM"},{"name":"Namibie","code":"NA"},{"name":"Nauru","code":"NR"},{"name":"Německo","code":"DE"},{"name":"Nepál","code":"NP"},{"name":"Niger","code":"NE"},{"name":"Nigérie","code":"NG"},{"name":"Nikaragua","code":"NI"},{"name":"Niue","code":"NU"},{"name":"Nizozemsko","code":"NL"},{"name":"Norfolkský ostrov","code":"NF"},{"name":"Norsko","code":"NO"},{"name":"Nová Kaledonie","code":"NC"},{"name":"Nový Zéland","code":"NZ"},{"name":"Omán","code":"OM"},{"name":"Ostrov Man","code":"IM"},{"name":"Pákistán","code":"PK"},{"name":"Palau","code":"PW"},{"name":"Palestinský stát","code":"PS"},{"name":"Panama","code":"PA"},{"name":"Panenské ostrovy, americké","code":"VI"},{"name":"Panenské ostrovy, britské","code":"VG"},{"name":"Papua Nová Guinea","code":"PG"},{"name":"Paraguay","code":"PY"},{"name":"Peru","code":"PE"},{"name":"Pitcairnovy ostrovy","code":"PN"},{"name":"Pobřeží slonoviny","code":"CI"},{"name":"Polsko","code":"PL"},{"name":"Portoriko","code":"PR"},{"name":"Portugalsko","code":"PT"},{"name":"Rakousko","code":"AT"},{"name":"Řecko","code":"GR"},{"name":"Réunion","code":"RE"},{"name":"Rovníková Guinea","code":"GQ"},{"name":"Rumunsko","code":"RO"},{"name":"Ruská federace","code":"RU"},{"name":"Rwanda","code":"RW"},{"name":"Šalamounovy ostrovy","code":"SB"},{"name":"Salvador","code":"SV"},{"name":"Samoa","code":"WS"},{"name":"San Marino","code":"SM"},{"name":"Saúdská Arábie","code":"SA"},{"name":"Senegal","code":"SN"},{"name":"Severní Mariany","code":"MP"},{"name":"Seychely","code":"SC"},{"name":"Sierra Leone","code":"SL"},{"name":"Singapur","code":"SG"},{"name":"Slovensko","code":"SK"},{"name":"Slovinsko","code":"SI"},{"name":"Somálsko","code":"SO"},{"name":"Španělsko","code":"ES"},{"name":"Spojené arabské emiráty","code":"AE"},{"name":"Spojené království","code":"GB"},{"name":"Spojené státy","code":"US"},{"name":"Srbsko","code":"RS"},{"name":"Šrí Lanka","code":"LK"},{"name":"Středoafrická republika","code":"CF"},{"name":"Súdán","code":"SD"},{"name":"Surinam","code":"SR"},{"name":"Svalbard a Jan Mayen","code":"SJ"},{"name":"Svatá Helena, Ascension a Tristan da Cunha","code":"SH"},{"name":"Svatá Lucie","code":"LC"},{"name":"Svatý Bartoloměj","code":"BL"},{"name":"Svatý Kryštof a Nevis","code":"KN"},{"name":"Svatý Martin (francouzská část)","code":"MF"},{"name":"Svatý Martin (nizozemská část)","code":"SX"},{"name":"Svatý Pierre a Miquelon","code":"PM"},{"name":"Svatý Tomáš a Princův ostrov","code":"ST"},{"name":"Svatý Vincenc a Grenadiny","code":"VC"},{"name":"Svatý stolec (Vatikánský městský stát)","code":"VA"},{"name":"Svazijsko","code":"SZ"},{"name":"Švédsko","code":"SE"},{"name":"Švýcarsko","code":"CH"},{"name":"Syrská arabská republika","code":"SY"},{"name":"Tádžikistán","code":"TJ"},{"name":"Tanzanie, sjednocená republika","code":"TZ"},{"name":"Tchaj-wan","code":"TW"},{"name":"Thajsko","code":"TH"},{"name":"Togo","code":"TG"},{"name":"Tokelau","code":"TK"},{"name":"Tonga","code":"TO"},{"name":"Trinidad a Tobago","code":"TT"},{"name":"Tunisko","code":"TN"},{"name":"Turecko","code":"TR"},{"name":"Turkmenistán","code":"TM"},{"name":"Turks a Caicos","code":"TC"},{"name":"Tuvalu","code":"TV"},{"name":"Uganda","code":"UG"},{"name":"Ukrajina","code":"UA"},{"name":"Uruguay","code":"UY"},{"name":"Uzbekistán","code":"UZ"},{"name":"Vánoční ostrov","code":"CX"},{"name":"Vanuatu","code":"VU"},{"name":"Vietnam","code":"VN"},{"name":"Východní Timor","code":"TL"},{"name":"Wallis a Futuna","code":"WF"},{"name":"Zambie","code":"ZM"},{"name":"Západní Sahara","code":"EH"},{"name":"Zimbabwe","code":"ZW"}]

countries.en.json

[{"name":"Afghanistan","code":"AF"},{"name":"Åland Islands","code":"AX"},{"name":"Albania","code":"AL"},{"name":"Algeria","code":"DZ"},{"name":"American Samoa","code":"AS"},{"name":"Andorra","code":"AD"},{"name":"Angola","code":"AO"},{"name":"Anguilla","code":"AI"},{"name":"Antarctica","code":"AQ"},{"name":"Antigua and Barbuda","code":"AG"},{"name":"Argentina","code":"AR"},{"name":"Armenia","code":"AM"},{"name":"Aruba","code":"AW"},{"name":"Australia","code":"AU"},{"name":"Austria","code":"AT"},{"name":"Azerbaijan","code":"AZ"},{"name":"Bahamas","code":"BS"},{"name":"Bahrain","code":"BH"},{"name":"Bangladesh","code":"BD"},{"name":"Barbados","code":"BB"},{"name":"Belarus","code":"BY"},{"name":"Belgium","code":"BE"},{"name":"Belize","code":"BZ"},{"name":"Benin","code":"BJ"},{"name":"Bermuda","code":"BM"},{"name":"Bhutan","code":"BT"},{"name":"Bolivia, Plurinational State of","code":"BO"},{"name":"Bonaire, Sint Eustatius and Saba","code":"BQ"},{"name":"Bosnia and Herzegovina","code":"BA"},{"name":"Botswana","code":"BW"},{"name":"Bouvet Island","code":"BV"},{"name":"Brazil","code":"BR"},{"name":"British Indian Ocean Territory","code":"IO"},{"name":"Brunei Darussalam","code":"BN"},{"name":"Bulgaria","code":"BG"},{"name":"Burkina Faso","code":"BF"},{"name":"Burundi","code":"BI"},{"name":"Cambodia","code":"KH"},{"name":"Cameroon","code":"CM"},{"name":"Canada","code":"CA"},{"name":"Cape Verde","code":"CV"},{"name":"Cayman Islands","code":"KY"},{"name":"Central African Republic","code":"CF"},{"name":"Chad","code":"TD"},{"name":"Chile","code":"CL"},{"name":"China","code":"CN"},{"name":"Christmas Island","code":"CX"},{"name":"Cocos (Keeling) Islands","code":"CC"},{"name":"Colombia","code":"CO"},{"name":"Comoros","code":"KM"},{"name":"Congo","code":"CG"},{"name":"Congo, The Democratic Republic of the","code":"CD"},{"name":"Cook Islands","code":"CK"},{"name":"Costa Rica","code":"CR"},{"name":"Côte d'Ivoire","code":"CI"},{"name":"Croatia","code":"HR"},{"name":"Cuba","code":"CU"},{"name":"Curaçao","code":"CW"},{"name":"Cyprus","code":"CY"},{"name":"Czech Republic","code":"CZ"},{"name":"Denmark","code":"DK"},{"name":"Djibouti","code":"DJ"},{"name":"Dominica","code":"DM"},{"name":"Dominican Republic","code":"DO"},{"name":"Ecuador","code":"EC"},{"name":"Egypt","code":"EG"},{"name":"El Salvador","code":"SV"},{"name":"Equatorial Guinea","code":"GQ"},{"name":"Eritrea","code":"ER"},{"name":"Estonia","code":"EE"},{"name":"Ethiopia","code":"ET"},{"name":"Falkland Islands (Malvinas)","code":"FK"},{"name":"Faroe Islands","code":"FO"},{"name":"Fiji","code":"FJ"},{"name":"Finland","code":"FI"},{"name":"France","code":"FR"},{"name":"French Guiana","code":"GF"},{"name":"French Polynesia","code":"PF"},{"name":"French Southern Territories","code":"TF"},{"name":"Gabon","code":"GA"},{"name":"Gambia","code":"GM"},{"name":"Georgia","code":"GE"},{"name":"Germany","code":"DE"},{"name":"Ghana","code":"GH"},{"name":"Gibraltar","code":"GI"},{"name":"Greece","code":"GR"},{"name":"Greenland","code":"GL"},{"name":"Grenada","code":"GD"},{"name":"Guadeloupe","code":"GP"},{"name":"Guam","code":"GU"},{"name":"Guatemala","code":"GT"},{"name":"Guernsey","code":"GG"},{"name":"Guinea","code":"GN"},{"name":"Guinea-Bissau","code":"GW"},{"name":"Guyana","code":"GY"},{"name":"Haiti","code":"HT"},{"name":"Heard Island and McDonald Islands","code":"HM"},{"name":"Holy See (Vatican City State)","code":"VA"},{"name":"Honduras","code":"HN"},{"name":"Hong Kong","code":"HK"},{"name":"Hungary","code":"HU"},{"name":"Iceland","code":"IS"},{"name":"India","code":"IN"},{"name":"Indonesia","code":"ID"},{"name":"Iran, Islamic Republic of","code":"IR"},{"name":"Iraq","code":"IQ"},{"name":"Ireland","code":"IE"},{"name":"Isle of Man","code":"IM"},{"name":"Israel","code":"IL"},{"name":"Italy","code":"IT"},{"name":"Jamaica","code":"JM"},{"name":"Japan","code":"JP"},{"name":"Jersey","code":"JE"},{"name":"Jordan","code":"JO"},{"name":"Kazakhstan","code":"KZ"},{"name":"Kenya","code":"KE"},{"name":"Kiribati","code":"KI"},{"name":"Korea, Democratic People's Republic of","code":"KP"},{"name":"Korea, Republic of","code":"KR"},{"name":"Kuwait","code":"KW"},{"name":"Kyrgyzstan","code":"KG"},{"name":"Lao People's Democratic Republic","code":"LA"},{"name":"Latvia","code":"LV"},{"name":"Lebanon","code":"LB"},{"name":"Lesotho","code":"LS"},{"name":"Liberia","code":"LR"},{"name":"Libya","code":"LY"},{"name":"Liechtenstein","code":"LI"},{"name":"Lithuania","code":"LT"},{"name":"Luxembourg","code":"LU"},{"name":"Macao","code":"MO"},{"name":"Macedonia, Republic of","code":"MK"},{"name":"Madagascar","code":"MG"},{"name":"Malawi","code":"MW"},{"name":"Malaysia","code":"MY"},{"name":"Maldives","code":"MV"},{"name":"Mali","code":"ML"},{"name":"Malta","code":"MT"},{"name":"Marshall Islands","code":"MH"},{"name":"Martinique","code":"MQ"},{"name":"Mauritania","code":"MR"},{"name":"Mauritius","code":"MU"},{"name":"Mayotte","code":"YT"},{"name":"Mexico","code":"MX"},{"name":"Micronesia, Federated States of","code":"FM"},{"name":"Moldova, Republic of","code":"MD"},{"name":"Monaco","code":"MC"},{"name":"Mongolia","code":"MN"},{"name":"Montenegro","code":"ME"},{"name":"Montserrat","code":"MS"},{"name":"Morocco","code":"MA"},{"name":"Mozambique","code":"MZ"},{"name":"Myanmar","code":"MM"},{"name":"Namibia","code":"NA"},{"name":"Nauru","code":"NR"},{"name":"Nepal","code":"NP"},{"name":"Netherlands","code":"NL"},{"name":"New Caledonia","code":"NC"},{"name":"New Zealand","code":"NZ"},{"name":"Nicaragua","code":"NI"},{"name":"Niger","code":"NE"},{"name":"Nigeria","code":"NG"},{"name":"Niue","code":"NU"},{"name":"Norfolk Island","code":"NF"},{"name":"Northern Mariana Islands","code":"MP"},{"name":"Norway","code":"NO"},{"name":"Oman","code":"OM"},{"name":"Pakistan","code":"PK"},{"name":"Palau","code":"PW"},{"name":"Palestine, State of","code":"PS"},{"name":"Panama","code":"PA"},{"name":"Papua New Guinea","code":"PG"},{"name":"Paraguay","code":"PY"},{"name":"Peru","code":"PE"},{"name":"Philippines","code":"PH"},{"name":"Pitcairn","code":"PN"},{"name":"Poland","code":"PL"},{"name":"Portugal","code":"PT"},{"name":"Puerto Rico","code":"PR"},{"name":"Qatar","code":"QA"},{"name":"Réunion","code":"RE"},{"name":"Romania","code":"RO"},{"name":"Russian Federation","code":"RU"},{"name":"Rwanda","code":"RW"},{"name":"Saint Barthélemy","code":"BL"},{"name":"Saint Helena, Ascension and Tristan da Cunha","code":"SH"},{"name":"Saint Kitts and Nevis","code":"KN"},{"name":"Saint Lucia","code":"LC"},{"name":"Saint Martin (French part)","code":"MF"},{"name":"Saint Pierre and Miquelon","code":"PM"},{"name":"Saint Vincent and the Grenadines","code":"VC"},{"name":"Samoa","code":"WS"},{"name":"San Marino","code":"SM"},{"name":"Sao Tome and Principe","code":"ST"},{"name":"Saudi Arabia","code":"SA"},{"name":"Senegal","code":"SN"},{"name":"Serbia","code":"RS"},{"name":"Seychelles","code":"SC"},{"name":"Sierra Leone","code":"SL"},{"name":"Singapore","code":"SG"},{"name":"Sint Maarten (Dutch part)","code":"SX"},{"name":"Slovakia","code":"SK"},{"name":"Slovenia","code":"SI"},{"name":"Solomon Islands","code":"SB"},{"name":"Somalia","code":"SO"},{"name":"South Africa","code":"ZA"},{"name":"South Georgia and the South Sandwich Islands","code":"GS"},{"name":"South Sudan","code":"SS"},{"name":"Spain","code":"ES"},{"name":"Sri Lanka","code":"LK"},{"name":"Sudan","code":"SD"},{"name":"Suriname","code":"SR"},{"name":"Svalbard and Jan Mayen","code":"SJ"},{"name":"Swaziland","code":"SZ"},{"name":"Sweden","code":"SE"},{"name":"Switzerland","code":"CH"},{"name":"Syrian Arab Republic","code":"SY"},{"name":"Taiwan","code":"TW"},{"name":"Tajikistan","code":"TJ"},{"name":"Tanzania, United Republic of","code":"TZ"},{"name":"Thailand","code":"TH"},{"name":"Timor-Leste","code":"TL"},{"name":"Togo","code":"TG"},{"name":"Tokelau","code":"TK"},{"name":"Tonga","code":"TO"},{"name":"Trinidad and Tobago","code":"TT"},{"name":"Tunisia","code":"TN"},{"name":"Turkey","code":"TR"},{"name":"Turkmenistan","code":"TM"},{"name":"Turks and Caicos Islands","code":"TC"},{"name":"Tuvalu","code":"TV"},{"name":"Uganda","code":"UG"},{"name":"Ukraine","code":"UA"},{"name":"United Arab Emirates","code":"AE"},{"name":"United Kingdom","code":"GB"},{"name":"United States","code":"US"},{"name":"United States Minor Outlying Islands","code":"UM"},{"name":"Uruguay","code":"UY"},{"name":"Uzbekistan","code":"UZ"},{"name":"Vanuatu","code":"VU"},{"name":"Venezuela, Bolivarian Republic of","code":"VE"},{"name":"Viet Nam","code":"VN"},{"name":"Virgin Islands, British","code":"VG"},{"name":"Virgin Islands, U.S.","code":"VI"},{"name":"Wallis and Futuna","code":"WF"},{"name":"Western Sahara","code":"EH"},{"name":"Yemen","code":"YE"},{"name":"Zambia","code":"ZM"},{"name":"Zimbabwe","code":"ZW"}]