You can use this csv file : country code list into a CSV.

import csv

dic = {}
with open("wikipedia-iso-country-codes.csv") as f:
    file= csv.DictReader(f, delimiter=',')
    for line in file:
        dic[line['English short name lower case']] = line['Alpha-2 code']        

countries = ['American Samoa', 'Canada', 'France']

for country in countries:
    print(dic[country])

Will print:

AS
CA
FR

Few more alternatives.

You can use pycountry to get a list of all the countries:

pip install pycountry 

Or you can use this dictionary:

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

Update 2021: The module has been updated including shortcomings mentioned by @JurajBezručka