Implemented Deck

draw and shuffle functionality

poker/__init__.py

@@ -1,24 +1,25 @@
 # ruff: noqa: F401
 
 from poker._common import PokerEnum
-from poker.card import Suit, Rank, Card, FACE_RANKS, BROADWAY_RANKS
-from poker.hand import (
-    Shape,
-    Hand,
-    Combo,
-    Range,
-    PAIR_HANDS,
-    OFFSUIT_HANDS,
-    SUITED_HANDS,
-)
+from poker.card import BROADWAY_RANKS, FACE_RANKS, Card, Rank, Suit
 from poker.constants import (
-    PokerRoom,
+    Action,
     Currency,
     Game,
     GameType,
     Limit,
     MoneyType,
-    Action,
+    PokerRoom,
     Position,
 )
+from poker.deck import Deck
+from poker.hand import (
+    OFFSUIT_HANDS,
+    PAIR_HANDS,
+    SUITED_HANDS,
+    Combo,
+    Hand,
+    Range,
+    Shape,
+)
 from poker.strategy import Strategy

poker/deck.py

@@ -0,0 +1,27 @@
+import secrets
+
+from .card import Card
+
+
+class Deck:
+    def __init__(self):
+        self._cards = list(Card)
+        self._drawn = []
+
+    def shuffle(self):
+        """Shuffles the deck."""
+        # Algorithm taken from the Python standard library 3.12 Random.shuffle,
+        # which is based on the Fisher-Yates shuffle.
+        for i in range(len(self._cards) - 1, 0, -1):
+            # pick an element in cards[:i+1] with which to exchange cards[i]
+            j = secrets.randbelow(i + 1)
+            self._cards[i], self._cards[j] = self._cards[j], self._cards[i]
+
+    def __len__(self):
+        return len(self._cards)
+
+    def draw(self):
+        """Draws a card from the top of the deck."""
+        card = self._cards.pop()
+        self._drawn.append(card)
+        return card

tests/test_deck.py

@@ -0,0 +1,27 @@
+from poker import Card, Deck
+
+
+def test_initial_state():
+    deck = Deck()
+    assert len(deck) == 52
+    assert deck._drawn == []
+    assert deck._cards == list(Card)
+
+
+def test_draw():
+    deck = Deck()
+    card = deck.draw()
+    assert len(deck) == 51
+    assert card not in deck._cards
+    assert deck._drawn == [card]
+
+
+def test_shuffle():
+    deck = Deck()
+    deck2 = Deck()
+    assert deck._cards == deck2._cards
+
+    deck3 = Deck()
+    deck3.shuffle()
+    assert deck._cards != deck3._cards
+    assert deck2._cards != deck3._cards