I’ve been considering fast poker hand evaluation in Python. It occurred to me that one way to speed the process up would be to represent all the card faces and suits as prime numbers and multiply them together to represent the hands. To whit:
class PokerCard: faces="23456789TJQKA" suits="cdhs" facePrimes = [11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 53, 59, 61] suitPrimes = [2, 3, 5, 7]
def HashVal(self): return PokerCard.facePrimes[self.cardFace] * PokerCard.suitPrimes[self.cardSuit]
This would give each hand a numeric value that, through modulo could tell me how many kings are in the hand or how many hearts. For example, any hand with five or more clubs in it would divide evenly by 2^5; any hand with four kings would divide evenly by 59^4, etc.
The problem is that a seven-card hand like AcAdAhAsKdKhKs has a hash value of approximately 62.7 quadrillion, which would take considerably more than 32 bits to represent internally. Is there a way to store such large numbers in Python that will allow me to perform arithmetic operations on it?