interpreter.py

# --------------------------------------------------------
# Licensed under the terms of the BSD 3-Clause License
# (see LICENSE for details).
# Copyright © 2018-2024, A.A Suvorov
# All rights reserved.
# --------------------------------------------------------
# https://github.com/smartlegionlab/
# --------------------------------------------------------
"""Interpreter"""


class RomanNumeralInterpreter:
    """Roman numeral interpreter"""
    def __init__(self):
        self.grammar = {
            'I': 1,
            'V': 5,
            'X': 10,
            'L': 50,
            'C': 100,
            'D': 500,
            'M': 1000
        }

    def interpret(self, text):
        numbers = list(map(self.grammar.get, text))
        if None in numbers:
            raise ValueError('Wrong value: %s' % text)
        result = 0
        temp = None
        while numbers:
            num = numbers.pop(0)
            if temp is None or temp >= num:
                result += num
            else:
                result += (num - temp * 2)
            temp = num
        return result


def main():
    interp = RomanNumeralInterpreter()
    print(interp.interpret('MMMCMXCIX') == 3999)  # True
    print(interp.interpret('MCMLXXXVIII') == 1988)  # True


if __name__ == '__main__':
    main()