odds.py

import numpy as np
from fractions import Fraction
import pandas as pd
from odo import odo


def dec2percent (dec):
    """dec2percent(2)
    """
    return np.reciprocal(float(dec))


def fractional2percent (fractional):
    """fractional2percent(Fraction(3,1))
    """
    return float(fractional.denominator) /(fractional.denominator + fractional.numerator)


def moneyline2percent(moneyline):
    percent = 0.0
    if np.sign(moneyline) < 0:
        percent = (-1*moneyline) / ( -1.0*moneyline+100 )
    else:
        percent = 100 / (moneyline + 100.0)
    return percent


def percent2dec (percent):
    """percent2dec(.5)
    """
    return np.reciprocal(percent)


def percent2fractional (percent):
    return Fraction(np.reciprocal(percent)-1).limit_denominator(100)


def percent2moneyline(percent):
    if percent > .5:
        return  (percent / (1 - percent) ) * -100
    else:
        return  ( (1 - percent) / percent )  * 100


if __name__ == '__main__':
    """
    parimutuel betting example with odds, payouts for win, place, show
    """

    df = pd.DataFrame({
         'betters': ['fred', 'barney' ,'wilma', 'tom' ,'john' ,'jerry','tom','mo','larry','eddie']
        ,'bets' :   [100 ,200, 100, 50 ,20 ,30 ,100,20,40,60]
        ,'horse' :  ['cigar' , 'brownie' , 'neptune', 'neptune','cigar','delroy','cigar','delroy','neptune','neptune']
        ,'type' :   ['win', 'win', 'win' ,'win', 'win', 'win' , 'place', 'place', 'place','place']
        })
    pdf = df[df.type=='place']
    sdf = df[df.type=='show']
    wdf = df[df.type=='win']

    bets = df[['bets','betters','horse','type']]

    x= wdf.groupby('horse',as_index=False)['bets'].sum()
    wdf= wdf.merge(x,on=['horse'])
    wdf['pcttotal'] = wdf.bets_x / wdf.bets_y
    wdf['payout']  = wdf.bets_x.sum() * wdf.pcttotal
    wdf = wdf.rename(columns={'bets_x':'bets','bets_y': 'totamtperhorse'})
    wdf['decodds'] = wdf.bets.sum() / wdf.totamtperhorse
    wdf['percent'] = wdf.decodds.apply(np.reciprocal)
    wdf['moneyline'] = wdf.percent.apply(percent2moneyline)
    wdf['fractional'] =  wdf.percent.apply(percent2fractional)
    wdf['fractional']=wdf.fractional.apply(str)

    tote = wdf[['horse','fractional','decodds','percent','moneyline','totamtperhorse']].drop_duplicates()



    def placeOrshow (pdf,*args):
        """placeOrshow(pdf,'cigar','neptune')
        """
        pool = pdf.bets.sum()
        z= pdf.groupby('horse',as_index=False)['bets'].sum()
        pdf= pdf.merge(z,on=['horse'])
        pdf= pdf[pdf.horse.isin(args)]
        profit = pool - pdf.bets_x.sum()
        pdf['pcttotal'] = pdf.bets_x / pdf.bets_y
        split = len(args) - len(set(args).difference(set(pdf.horse)) )
        pdf['payout'] = profit / split * pdf.pcttotal + pdf.bets_x
        return [pool,pdf]



    odo(tote,'sqlite:///bettingwindow.db::toteboard')
    odo(bets,'sqlite:///bettingwindow.db::bets')

    print placeOrshow(pdf,'cigar','neptune')