pg.181

.ipynb_checkpoints/default-54e50c86-af21-45a9-8ae4-b8d7ed2804d9-checkpoint.ipynb

@@ -0,0 +1,6 @@
+{
+ "cells": [],
+ "metadata": {},
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

Part_3-Fuctions_as_Objects/Chap_6-Design_Patterns_With_First_Class_Funcions/ex_6_3__functional_strategy.py

@@ -0,0 +1,57 @@
+from collections import namedtuple
+
+Customer = namedtuple('Customer', 'name fidelity')
+
+
+class LineItem:
+
+    def __init__(self, product, quantity, price):
+        self.product = product
+        self.quantity = quantity
+        self.price = price
+
+    def total (self):
+        return self.price * self.quantity
+
+
+class Order:  # the Context
+
+    def __init__(self, customer, cart, promotion = None):
+        self.customer = customer
+        self.cart = list(cart)
+        self.promotion = promotion
+
+    def total(self):
+        if not hasattr(self, '__total'):
+            self.__total = sum(item.total() for item in self.cart)
+        return self.__total
+
+    def due(self):
+        if self.promotion is None:
+            discount = 0
+        else:
+            discount = self.promotion(self)
+        return self.total() - discount
+
+    def __repr__(self):
+        fmt = '<Order total: {:.2f} due: {:.2f}>'
+        return fmt.format(self.total(), self.due())
+
+def fidelity_promo(order):
+    """5% discount for customers with 1000 or more fidelity points"""
+    return order.total() * .05 if order.customer.fidelity >- 1000 else 0
+
+def bulk_item_promo(order):
+    """10% discount for each LineItem with 20 or more units"""
+    discount = 0
+    for item in order.cart:
+        if item.quantity >= 20:
+            discount += item.total() * .1
+    return discount
+
+def large_order_promo(order):
+    """7% discount for orders with 10 or more items"""
+    distinct_items = {item.product for item in order.cart}
+    if len(distinct_items) >= 10:
+        return order.total() * .07
+    return 0

Part_3-Fuctions_as_Objects/Chap_6-Design_Patterns_With_First_Class_Funcions/ex_6_4__example_function_strategy.ipynb

@@ -0,0 +1,140 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "<Order total: 42.00 due: 39.90>"
+      ]
+     },
+     "execution_count": 1,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "from ex_6_3__functional_strategy import (\n",
+    "    Customer,\n",
+    "    LineItem,\n",
+    "    Order,\n",
+    "    fidelity_promo,\n",
+    "    bulk_item_promo,\n",
+    "    large_order_promo,\n",
+    ")\n",
+    "joe = Customer('John Doe', 0)\n",
+    "ann = Customer('Ann Smith', 1100)\n",
+    "cart = [\n",
+    "    LineItem('banana', 4, .5),\n",
+    "    LineItem('apple', 10, 1.5),\n",
+    "    LineItem('watermellon', 5, 5.0),\n",
+    "]\n",
+    "Order(joe, cart, fidelity_promo)\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "<Order total: 42.00 due: 39.90>"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "Order(ann, cart, fidelity_promo)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "<Order total: 30.00 due: 28.50>"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "banana_cart = [\n",
+    "    LineItem('banana', 30, .5),\n",
+    "    LineItem('apple', 10, 1.5),\n",
+    "]\n",
+    "Order(joe, banana_cart, bulk_item_promo)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "NameError",
+     "evalue": "name 'large_order_promo' is not defined",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mNameError\u001b[0m                                 Traceback (most recent call last)",
+      "\u001b[0;32m<ipython-input-4-80e58dad44d7>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[1;32m      3\u001b[0m     \u001b[0;32mfor\u001b[0m \u001b[0mitem_code\u001b[0m \u001b[0;32min\u001b[0m \u001b[0mrange\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;36m10\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      4\u001b[0m ]\n\u001b[0;32m----> 5\u001b[0;31m \u001b[0mOrder\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mjoe\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mlong_order\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mlarge_order_promo\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
+      "\u001b[0;31mNameError\u001b[0m: name 'large_order_promo' is not defined"
+     ]
+    }
+   ],
+   "source": [
+    "long_order = [\n",
+    "    LineItem(str(item_code), 1, 1.0)\n",
+    "    for item_code in range(10)\n",
+    "]\n",
+    "Order(joe, long_order, large_order_promo)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "interpreter": {
+   "hash": "916dbcbb3f70747c44a77c7bcd40155683ae19c65e1c03b4aa3499c5328201f1"
+  },
+  "kernelspec": {
+   "display_name": "Python 3.8.10 64-bit",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.10"
+  },
+  "orig_nbformat": 4
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

default-54e50c86-af21-45a9-8ae4-b8d7ed2804d9.ipynb

@@ -0,0 +1,6 @@
+{
+ "cells": [],
+ "metadata": {},
+ "nbformat": 4,
+ "nbformat_minor": 5
+}