Spoken numbers and roman numerals

numbers.py

# -*- coding: utf-8 -*-

import sys

def int_to_roman(input):
   """
   Convert an integer to Roman numerals.

   Examples:
   >>> int_to_roman(0)
   Traceback (most recent call last):
   ValueError: Argument must be between 1 and 3999

   >>> int_to_roman(-1)
   Traceback (most recent call last):
   ValueError: Argument must be between 1 and 3999

   >>> int_to_roman(1.5)
   Traceback (most recent call last):
   TypeError: expected integer, got <type 'float'>

   >>> for i in range(1, 21): print int_to_roman(i)
   ...
   I
   II
   III
   IV
   V
   VI
   VII
   VIII
   IX
   X
   XI
   XII
   XIII
   XIV
   XV
   XVI
   XVII
   XVIII
   XIX
   XX
   >>> print int_to_roman(2000)
   MM
   >>> print int_to_roman(1999)
   MCMXCIX
   """
   if type(input) != type(1):
      raise TypeError, "expected integer, got %s" % type(input)
   if not 0 < input < 4000:
      raise ValueError, "Argument must be between 1 and 3999"
   ints = (1000, 900,  500, 400, 100,  90, 50,  40, 10,  9,   5,  4,   1)
   nums = ('M',  'CM', 'D', 'CD','C', 'XC','L','XL','X','IX','V','IV','I')
   result = ""
   for i in range(len(ints)):
      count = int(input / ints[i])
      result += nums[i] * count
      input -= ints[i] * count
   return result


## {{{ http://code.activestate.com/recipes/413172/ (r3)
_known = {
    0: 'zero',
    1: 'one',
    2: 'two',
    3: 'three',
    4: 'four',
    5: 'five',
    6: 'six',
    7: 'seven',
    8: 'eight',
    9: 'nine',
    10: 'ten',
    11: 'eleven',
    12: 'twelve',
    13: 'thirteen',
    14: 'fourteen',
    15: 'fifteen',
    16: 'sixteen',
    17: 'seventeen',
    18: 'eighteen',
    19: 'nineteen',
    20: 'twenty',
    30: 'thirty',
    40: 'forty',
    50: 'fifty',
    60: 'sixty',
    70: 'seventy',
    80: 'eighty',
    90: 'ninety'
    }
def _positive_spoken_number(n):
    """Assume n is a positive integer.
    >>> _positive_spoken_number(900)
    'nine hundred'
    >>> _positive_spoken_number(100)
    'one hundred'
    >>> _positive_spoken_number(100000000000)
    'one hundred billion'
    >>> _positive_spoken_number(1000000000000)
    'one trillion'
    >>> _positive_spoken_number(33000000000000)
    'thirty-three trillion'
    >>> _positive_spoken_number(34954523539)
    'thirty-four billion, nine hundred fifty-four million, five hundred twenty-three thousand, five hundred thirty-nine'
    """
    #import sys; print >>sys.stderr, n
    if n in _known:
        return _known[n]
    bestguess = str(n)
    remainder = 0
    if n<=20:
        print >>sys.stderr, n, "How did this happen?"
        assert 0
    elif n < 100:
        bestguess= _positive_spoken_number((n//10)*10) + '-' + \
                   _positive_spoken_number(n%10)
        return bestguess
    elif n < 1000:
        bestguess= _positive_spoken_number(n//100) + ' ' + 'hundred'
        remainder = n%100
    elif n < 1000000:
        bestguess= _positive_spoken_number(n//1000) + ' ' + 'thousand'
        remainder = n%1000
    elif n < 1000000000:
        bestguess= _positive_spoken_number(n//1000000) + ' ' + 'million'
        remainder = n%1000000
    elif n < 1000000000000:
        bestguess= _positive_spoken_number(n//1000000000) + ' ' + 'billion'
        remainder = n%1000000000
    else:
        bestguess= _positive_spoken_number(n//1000000000000)+' '+'trillion'
        remainder = n%1000000000000
    if remainder:
        if remainder >= 100: comma = ','
        else:                comma = ''
        return bestguess + comma + ' ' + _positive_spoken_number(remainder)
    else:
        return bestguess

def spoken_number(n):
    """Return the number as it would be spoken, or just str(n) if unknown.
    >>> spoken_number(0)
    'zero'
    >>> spoken_number(1)
    'one'
    >>> spoken_number(2)
    'two'
    >>> spoken_number(-2)
    'minus two'
    >>> spoken_number(42)
    'forty-two'
    >>> spoken_number(-1011)
    'minus one thousand eleven'
    >>> spoken_number(1111)
    'one thousand, one hundred eleven'
    """
    if not isinstance(n, int) and not isinstance(n, long): return n
    if n<0:
        if n in _known: return _known[n]
        else:           return 'minus ' + _positive_spoken_number(-n)
    return _positive_spoken_number(n)


if __name__ == '__main__':
    print spoken_number(101).replace(' ', '-')
    print int_to_roman(23)
## end of http://code.activestate.com/recipes/413172/ }}}