Dice

dice.py

# -*- coding: utf-8 -*-
import re
import random

class Dice(object):
  def __init__(self, description):
    self._description = description
    match = re.search('(\d+)d(\d+)', description)
    if not match: raise Exception('Dice format error: %s' % description)
    self._number = int(match.group(1))
    self._side = int(match.group(2))
    match = re.search('([\+\-]\d+)$', description)
    self._bonus = int(match.group(1)) if match else 0

  def __str__(self):
    return self._description

  def roll(self):
    return sum([random.randint(1, self._side) for n in range(self._number)]) + self._bonus

if __name__ == '__main__':
  import unittest

  class Test(unittest.TestCase):
    def testNormal(self):
      dice = Dice("2d6+4")
      self.assertEqual(dice._number, 2)
      self.assertEqual(dice._side, 6)
      self.assertEqual(dice._bonus, 4)

    def testMinusBonus(self):
      dice = Dice("3d7-2")
      self.assertEqual(dice._number, 3)
      self.assertEqual(dice._side, 7)
      self.assertEqual(dice._bonus, -2)

    def testNoBonus(self):
      dice = Dice("4d6")
      self.assertEqual(dice._number, 4)
      self.assertEqual(dice._side, 6)
      self.assertEqual(dice._bonus, 0)

    def testBigDice(self):
      dice = Dice("42d256+512")
      self.assertEqual(dice._number, 42)
      self.assertEqual(dice._side, 256)
      self.assertEqual(dice._bonus, 512)

    def testRoll(self):
      self.roll10Test("1d6")
      self.roll10Test("2d6")
      self.roll10Test("3d6")

    def testMaxMin(self):
      self.assertTrue(self.waitRoll("1d6", 1))
      self.assertTrue(self.waitRoll("1d6", 6))
      self.assertTrue(self.waitRoll("1d6+1", 7))
      self.assertTrue(self.waitRoll("2d6", 2))
      self.assertTrue(self.waitRoll("2d6", 12))
      self.assertTrue(self.waitRoll("2d6+4", 16))

    def testIgnoreFormat(self):
      self.assertRaises(Exception, Dice, 'd6')

    def waitRoll(self, dice, roll):
      d = Dice(dice)
      while True:
        if d.roll() != roll: continue
        return True

    def roll10Test(self, desc):
      print desc
      d = Dice(desc)
      print [d.roll() for n in range(10)]

    def testString(self):
      self.stringTest('1d6-2')
      self.stringTest('2d3+2')
      self.stringTest('3d6')

    def stringTest(self, desc):
      self.assertEqual(str(Dice(desc)), desc)

  unittest.main()