updated from Atlas

10-dp-1class-func/strategy_best.py

@@ -3,19 +3,20 @@
 # selecting best promotion from static list of functions
 
 """
+    >>> from strategy import Customer, LineItem
     >>> joe = Customer('John Doe', 0)
     >>> ann = Customer('Ann Smith', 1100)
-    >>> cart = [LineItem('banana', 4, .5),
-    ...         LineItem('apple', 10, 1.5),
-    ...         LineItem('watermelon', 5, 5.0)]
-    >>> banana_cart = [LineItem('banana', 30, .5),
-    ...                LineItem('apple', 10, 1.5)]
-    >>> big_cart = [LineItem(str(item_code), 1, 1.0)
+    >>> cart = [LineItem('banana', 4, Decimal('.5')),
+    ...         LineItem('apple', 10, Decimal('1.5')),
+    ...         LineItem('watermelon', 5, Decimal(5))]
+    >>> banana_cart = [LineItem('banana', 30, Decimal('.5')),
+    ...                LineItem('apple', 10, Decimal('1.5'))]
+    >>> long_cart = [LineItem(str(item_code), 1, Decimal(1))
     ...               for item_code in range(10)]
 
 # tag::STRATEGY_BEST_TESTS[]
 
-    >>> Order(joe, big_cart, best_promo)  # <1>
+    >>> Order(joe, long_cart, best_promo)  # <1>
     <Order total: 10.00 due: 9.30>
     >>> Order(joe, banana_cart, best_promo)  # <2>
     <Order total: 30.00 due: 28.50>
@@ -25,7 +26,9 @@
 # end::STRATEGY_BEST_TESTS[]
 """
 
-from strategy import Customer, LineItem, Order
+from decimal import Decimal
+
+from strategy import Order
 from strategy import fidelity_promo, bulk_item_promo, large_order_promo
 
 # tag::STRATEGY_BEST[]
@@ -33,9 +36,8 @@ from strategy import fidelity_promo, bulk_item_promo, large_order_promo
 promos = [fidelity_promo, bulk_item_promo, large_order_promo]  # <1>
 
 
-def best_promo(order) -> float:  # <2>
-    """Select best discount available
-    """
+def best_promo(order: Order) -> Decimal:  # <2>
+    """Compute the best discount available"""
     return max(promo(order) for promo in promos)  # <3>