fluent python

python_sandbox/python_sandbox/fluent_python/README.md

@@ -0,0 +1,2 @@
+# How to run tests?
+python -m pytest

python_sandbox/python_sandbox/fluent_python/python_data_model/cards.py

@@ -0,0 +1,25 @@
+import collections
+
+Card = collections.namedtuple("Card", ["rank", "suit"])
+
+
+class FrenchDeck:
+    ranks = [str(n) for n in range(2, 11)] + list("JQKA")
+    suits = "spades diamonds clubs hearts".split()
+
+    def __init__(self):
+        self._cards = [Card(rank, suit) for suit in self.suits for rank in self.ranks]
+
+    def __len__(self):
+        return len(self._cards)
+
+    def __getitem__(self, position):
+        return self._cards[position]
+
+
+suit_values = dict(spades=3, hearts=2, diamonds=1, clubs=0)
+
+
+def spades_high(card):
+    rank_value = FrenchDeck.ranks.index(card.rank)
+    return rank_value * len(suit_values) + suit_values[card.suit]

python_sandbox/python_sandbox/fluent_python/python_data_model/tests/test_cards.py

@@ -0,0 +1,40 @@
+from python_data_model.cards import Card, FrenchDeck, spades_high
+from random import choice
+import sys
+
+
+def test_cards():
+    print(f"sys.path: {sys.path}")
+    beer_card = Card("7", "diamonds")
+    assert beer_card.rank == "7"
+    assert beer_card.suit == "diamonds"
+
+
+def test_deck():
+    deck = FrenchDeck()
+    assert len(deck) == 52
+    assert deck[0] == Card("2", "spades")
+    assert deck[-1] == Card("A", "hearts")
+    # choice works with a sequence and FrenchDeck is a sequence because it implements
+    # both __len__ and __getitem__
+    print(f"Pick a random card: {choice(deck)}")
+    print(f"Pick a random card: {choice(deck)}")
+
+    # slicing works
+    assert deck[:3] == [Card("2", "spades"), Card("3", "spades"), Card("4", "spades")]
+    assert deck[-3:] == [Card("Q", "hearts"), Card("K", "hearts"), Card("A", "hearts")]
+
+    # iteration works too because of __getitem__
+    print("iterating cards")
+    for card in deck:
+        print(card)
+
+    # in works too
+    # If a collection has no __contains__ method, the "in" operator does a sequential scan
+    assert Card("Q", "hearts") in deck
+    assert Card("7", "beasts") not in deck
+
+    # sort cards
+    print("sorted cards")
+    for card in sorted(deck, key=spades_high):
+        print(card)

python_sandbox/python_sandbox/fluent_python/chapter1/vectors.py → python_sandbox/python_sandbox/fluent_python/python_data_model/vectors.py

@@ -7,7 +7,7 @@ def __init__(self, x=0, y=0):
         self.y = y
 
     def __repr__(self):
-        return 'Vector(%r, %r)' % (self.x, self.y)
+        return "Vector(%r, %r)" % (self.x, self.y)
 
     def __abs__(self):
         return hypot(self.x, self.y)
@@ -30,13 +30,13 @@ def __mul__(self, scalar):
 def main():
     v1 = Vector(2, 4)
     v2 = Vector(2, 1)
-    print('v1 + v2:', v1 + v2)
+    print("v1 + v2:", v1 + v2)
 
     v = Vector(3, 4)
-    print('abs(v):', abs(v))
+    print("abs(v):", abs(v))
 
-    print('v * 3:', v * 3)
+    print("v * 3:", v * 3)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()

python_sandbox/requirements.txt

@@ -1,2 +1,3 @@
 hydra-core==0.11.3
 pyyaml==5.3.1
+pytest==7.1.3