"""This module contains a code example related to
Think Python, 2nd Edition
by Allen Downey
http://thinkpython2.com
Copyright 2015 Allen Downey
License: http://creativecommons.org/licenses/by/4.0/
"""
from __future__ import print_function, division
from Card import Hand, Deck
class Hist(dict):
"""A map from each item (x) to its frequency."""
def __init__(self, seq=[]):
"Creates a new histogram starting with the items in seq."
for x in seq:
self.count(x)
def count(self, x, f=1):
"Increments (or decrements) the counter associated with item x."
self[x] = self.get(x, 0) + f
if self[x] == 0:
del self[x]
class PokerHand(Hand):
"""Represents a poker hand."""
all_labels = ['straightflush', 'fourkind', 'fullhouse', 'flush',
'straight', 'threekind', 'twopair', 'pair', 'highcard']
def make_histograms(self):
"""Computes histograms for suits and hands.
Creates attributes:
suits: a histogram of the suits in the hand.
ranks: a histogram of the ranks.
sets: a sorted list of the rank sets in the hand.
"""
self.suits = Hist()
self.ranks = Hist()
for c in self.cards:
self.suits.count(c.suit)
self.ranks.count(c.rank)
self.sets = list(self.ranks.values())
self.sets.sort(reverse=True)
def has_highcard(self):
"""Returns True if this hand has a high card."""
return len(self.cards)
def check_sets(self, *t):
"""Checks whether self.sets contains sets that are
at least as big as the requirements in t.
t: list of int
"""
for need, have in zip(t, self.sets):
if need > have:
return False
return True
def has_pair(self):
"""Checks whether this hand has a pair."""
return self.check_sets(2)
def has_twopair(self):
"""Checks whether this hand has two pair."""
return self.check_sets(2, 2)
def has_threekind(self):
"""Checks whether this hand has three of a kind."""
return self.check_sets(3)
def has_fourkind(self):
"""Checks whether this hand has four of a kind."""
return self.check_sets(4)
def has_fullhouse(self):
"""Checks whether this hand has a full house."""
return self.check_sets(3, 2)
def has_flush(self):
"""Checks whether this hand has a flush."""
for val in self.suits.values():
if val >= 5:
return True
return False
def has_straight(self):
"""Checks whether this hand has a straight."""
# make a copy of the rank histogram before we mess with it
ranks = self.ranks.copy()
ranks[14] = ranks.get(1, 0)
# see if we have 5 in a row
return self.in_a_row(ranks, 5)
def in_a_row(self, ranks, n=5):
"""Checks whether the histogram has n ranks in a row.
hist: map from rank to frequency
n: number we need to get to
"""
count = 0
for i in range(1, 15):
if ranks.get(i, 0):
count += 1
if count == n:
return True
else:
count = 0
return False
def has_straightflush(self):
"""Checks whether this hand has a straight flush.
Clumsy algorithm.
"""
# make a set of the (rank, suit) pairs we have
s = set()
for c in self.cards:
s.add((c.rank, c.suit))
if c.rank == 1:
s.add((14, c.suit))
# iterate through the suits and ranks and see if we
# get to 5 in a row
for suit in range(4):
count = 0
for rank in range(1, 15):
if (rank, suit) in s:
count += 1
if count == 5:
return True
else:
count = 0
return False
def has_straightflush(self):
"""Checks whether this hand has a straight flush.
Better algorithm (in the sense of being more demonstrably
correct).
"""
# partition the hand by suit and check each
# sub-hand for a straight
d = {}
for c in self.cards:
d.setdefault(c.suit, PokerHand()).add_card(c)
# see if any of the partitioned hands has a straight
for hand in d.values():
if len(hand.cards) < 5:
continue
hand.make_histograms()
if hand.has_straight():
return True
return False
def classify(self):
"""Classifies this hand.
Creates attributes:
labels:
"""
self.make_histograms()
self.labels = []
for label in PokerHand.all_labels:
f = getattr(self, 'has_' + label)
if f():
self.labels.append(label)
class PokerDeck(Deck):
"""Represents a deck of cards that can deal poker hands."""
def deal_hands(self, num_cards=5, num_hands=10):
"""Deals hands from the deck and returns Hands.
num_cards: cards per hand
num_hands: number of hands
returns: list of Hands
"""
hands = []
for i in range(num_hands):
hand = PokerHand()
self.move_cards(hand, num_cards)
hand.classify()
hands.append(hand)
return hands
def main():
# the label histogram: map from label to number of occurances
lhist = Hist()
# loop n times, dealing 7 hands per iteration, 7 cards each
n = 10000
for i in range(n):
if i % 1000 == 0:
print(i)
deck = PokerDeck()
deck.shuffle()
hands = deck.deal_hands(7, 7)
for hand in hands:
for label in hand.labels:
lhist.count(label)
# print the results
total = 7.0 * n
print(total, 'hands dealt:')
for label in PokerHand.all_labels:
freq = lhist.get(label, 0)
if freq == 0:
continue
p = total / freq
print('%s happens one time in %.2f' % (label, p))
if __name__ == '__main__':
main()