h/plugins/dice.py

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"""
dice.py: written by Scaevolus 2008, updated 2009
simulates dicerolls
"""
import re
import random
from util import hook
whitespace_re = re.compile(r'\s+')
valid_diceroll_re = re.compile(r'^[+-]?(\d+|\d*d\d+)([+-](\d+|\d*d\d+))*$')
sign_re = re.compile(r'[+-]?(?:\d*d)?\d+')
split_re = re.compile(r'([\d+-]*)d?(\d*)')
def nrolls(count, n):
"roll an n-sided die count times"
if n < 2: #it's a coin
if count < 5000:
return sum(random.randint(0, 1) for x in xrange(count))
else: #fake it
return int(random.normalvariate(.5*count, (.75*count)**.5))
else:
if count < 5000:
return sum(random.randint(1, n) for x in xrange(count))
else: #fake it
return int(random.normalvariate(.5*(1+n)*count,
(((n+1)*(2*n+1)/6.-(.5*(1+n))**2)*count)**.5))
@hook.command
def dice(inp):
".dice <diceroll> -- simulates dicerolls, e.g. .dice 2d20-d5+4 roll 2 " \
"D20s, subtract 1D5, add 4"
if not inp:
return dice.__doc__
spec = whitespace_re.sub('', inp)
if not valid_diceroll_re.match(spec):
return "Invalid diceroll"
sum = 0
groups = sign_re.findall(spec)
for roll in groups:
count, side = split_re.match(roll).groups()
if side == "":
sum += int(count)
else:
count = int(count) if count not in" +-" else 1
side = int(side)
try:
if count > 0:
sum += nrolls(count, side)
else:
sum -= nrolls(abs(count), side)
except OverflowError:
return "Thanks for overflowing a float, jerk >:["
return str(sum)