Kata Roman Numerals

Feel free to create a merge request on the codingdojo repository to suggest your own solution.

Python

``````#!/usr/bin/env python

def number_to_numeral(number):
"""
>>> number_to_numeral(1)
'I'
>>> number_to_numeral(2)
'II'
>>> number_to_numeral(12)
'XII'
>>> number_to_numeral(10)
'X'
>>> number_to_numeral(20)
'XX'
>>> number_to_numeral(99)
'XCIX'
>>> number_to_numeral(100)
'C'
>>> number_to_numeral(199)
'CXCIX'
>>> number_to_numeral(2399)
'MMCCCXCIX'
>>> number_to_numeral(4000)
Traceback (most recent call last):
...
IndexError: list index out of range

"""

numerals_dict = {
'ones':     ['', 'I', 'II', 'III', 'IV', 'V', 'VI', 'VII', 'VIII', 'IX'],
'tens':     ['', 'X', 'XX', 'XXX', 'XL', 'L', 'LX', 'LXX', 'LXXX', 'XC'],
'hundreds': ['', 'C', 'CC', 'CCC', 'CD', 'D', 'DC', 'DCC', 'DCCC', 'CM'],
'thousands': ['', 'M', 'MM', 'MMM'],
}

s = []
for index in ['ones', 'tens', 'hundreds', 'thousands']:
number, remainder = divmod(number, 10)
s.insert(0, numerals_dict[index][remainder])
return ''.join(s)
``````