Convert to and from Roman numerals.

This file is adapted from the roman package that is available on PyPI, which has the following copyright/license information:

Copyright (c) 2001 Mark Pilgrim

This program is free software; you can redistribute it and/or modify it under the terms of the Python 2.1.1 license, available at


to_roman(n, numpy.integer]) Convert an integer to a Roman numeral.
from_roman(s) Convert a Roman numeral to an integer.
is_roman_numeral(s) Check whether or not a string is a valid Roman numeral.