romain_numerals.py

ROMAN_DICTIONARY = {
    "I": 1,
    "II": 2,
    "III": 3,
    "V": 5,
    "X": 10,
    "L": 50,
    "C": 100,
    "D": 500,
    "M": 1000,
    "IV": 4,
    "IX": 9,
    "XL": 40,
    "XC": 90,
    "CD": 400,
    "CM": 900,
}

VALID_CHAR = [
    "II",
    "III",
    "IV",
    "IX",
    "XL",
    "XC",
    "CD",
    "CM",
    "I",
    "V",
    "X",
    "L",
    "C",
    "D",
    "M",
]


def roman_to_int(s: str) -> int:
    assert len(s) >= 1, "too short"
    assert len(s) <= 15, "too long"

    for char in s:
        assert char in VALID_CHAR, "Invalid Char"

    parsed = []
    for valid in VALID_CHAR:

        if valid in s:
            parsed.append(valid)
            s = s.replace(valid, "")

    sum = 0
    for p in parsed:
        sum += ROMAN_DICTIONARY[p]
        print(sum)
    return sum


assert roman_to_int("III") == 3
assert roman_to_int("IV") == 4
assert roman_to_int("IX") == 9
assert roman_to_int("LVIII") == 58
assert roman_to_int("MCMXCIV") == 1994