"roman numerals to integers converter with python using a dictionary" Code Answer

you have to make sure that you consume all characters that contribute to the sum. since all the multi-char "atomic" literals begin with the lower valued unit, and otherwise, higher valued units come first, a simple greedy approach is workable:

try to convert the first two chars as a whole, if that's not possible, convert the first single char.

move forward the appropriate number of steps.

def roman_int(user_roman):
    user_roman = user_roman.upper()
    resulti = 0

    while user_roman:
        # try first two chars
        if user_roman[:2] in roman_numerals:
            resulti += roman_numerals[user_roman[:2]]
            # cut off first two chars
            user_roman = user_roman[2:]
        # try first char
        elif user_roman[:1] in roman_numerals:
            resulti += roman_numerals[user_roman[:1]]
            # cut off first char
            user_roman = user_roman[1:]
        else:
            print('no roman number')
            return
    print(resulti)

By Suraksha Ajith on August 28 2022