{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Inventory Class"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [],
   "source": [
    "import csv                            # step 1\n",
    "\n",
    "class Inventory():                    # step 2\n",
    "    \n",
    "    def __init__(self, csv_filename): # step 3\n",
    "        with open(csv_filename) as f: # step 4\n",
    "            reader = csv.reader(f)\n",
    "            rows = list(reader)\n",
    "        self.header = rows[0]         # step 5\n",
    "        self.rows = rows[1:]\n",
    "        for row in self.rows:         # step 6\n",
    "            row[-1] = int(row[-1])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {
    "scrolled": true
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Id', 'Company', 'Product', 'TypeName', 'Inches', 'ScreenResolution', 'Cpu', 'Ram', 'Memory', 'Gpu', 'OpSys', 'Weight', 'Price_euros']\n",
      "1303\n"
     ]
    }
   ],
   "source": [
    "inventory = Inventory('laptops.csv')  # step 7\n",
    "print(inventory.header)               # step 8\n",
    "print(len(inventory.rows))            # step 9"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Finding a Laptop From the Id"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [],
   "source": [
    "import csv                            \n",
    "\n",
    "class Inventory():                    \n",
    "    \n",
    "    def __init__(self, csv_filename):\n",
    "        with open(csv_filename) as f: \n",
    "            reader = csv.reader(f)\n",
    "            rows = list(reader)\n",
    "        self.header = rows[0]        \n",
    "        self.rows = rows[1:]\n",
    "        for row in self.rows:              \n",
    "            row[-1] = int(row[-1])\n",
    "            \n",
    "    def get_laptop_from_id(self, laptop_id):   # step 1\n",
    "        for row in self.rows:                  # step 2\n",
    "            if row[0] == laptop_id:\n",
    "                return row\n",
    "        return None                            # step 3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['3362737', 'HP', '250 G6', 'Notebook', '15.6', 'Full HD 1920x1080', 'Intel Core i5 7200U 2.5GHz', '8GB', '256GB SSD', 'Intel HD Graphics 620', 'No OS', '1.86kg', 575]\n",
      "None\n"
     ]
    }
   ],
   "source": [
    "inventory = Inventory('laptops.csv')           # step 4\n",
    "print(inventory.get_laptop_from_id('3362737')) # step 5\n",
    "print(inventory.get_laptop_from_id('3362736')) # step 6"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Improving Id Lookups"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {},
   "outputs": [],
   "source": [
    "import csv                            \n",
    "\n",
    "class Inventory():                    \n",
    "    \n",
    "    def __init__(self, csv_filename):\n",
    "        with open(csv_filename) as f: \n",
    "            reader = csv.reader(f)\n",
    "            rows = list(reader)\n",
    "        self.header = rows[0]        \n",
    "        self.rows = rows[1:]\n",
    "        for row in self.rows:              \n",
    "            row[-1] = int(row[-1])\n",
    "        self.id_to_row = {}                         # step 1\n",
    "        for row in self.rows:                       # step 2\n",
    "            self.id_to_row[row[0]] = row \n",
    "    \n",
    "    def get_laptop_from_id(self, laptop_id):\n",
    "        for row in self.rows:                 \n",
    "            if row[0] == laptop_id:\n",
    "                return row\n",
    "        return None   \n",
    "    \n",
    "    def get_laptop_from_id_fast(self, laptop_id):   # step 3\n",
    "        if laptop_id in self.id_to_row:             # step 4\n",
    "            return self.id_to_row[laptop_id]\n",
    "        return None"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['3362737', 'HP', '250 G6', 'Notebook', '15.6', 'Full HD 1920x1080', 'Intel Core i5 7200U 2.5GHz', '8GB', '256GB SSD', 'Intel HD Graphics 620', 'No OS', '1.86kg', 575]\n",
      "None\n"
     ]
    }
   ],
   "source": [
    "inventory = Inventory('laptops.csv')                # step 5\n",
    "print(inventory.get_laptop_from_id_fast('3362737')) # step 6\n",
    "print(inventory.get_laptop_from_id_fast('3362736')) # step 7"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Comparing Performance"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0.5769174098968506\n",
      "0.0021619796752929688\n"
     ]
    }
   ],
   "source": [
    "import time                                                    # step 1\n",
    "import random                                                  # step 2\n",
    "\n",
    "ids = [random.randint(1000000, 9999999) for _ in range(10000)] # step 3\n",
    "\n",
    "inventory = Inventory('laptops.csv')                           # step 4\n",
    "\n",
    "total_time_no_dict = 0                                         # step 5\n",
    "for id in ids:                                                 # step 6\n",
    "    start = time.time()                                        # step 6.1\n",
    "    inventory.get_laptop_from_id(id)                           # step 6.2\n",
    "    end = time.time()                                          # step 6.3\n",
    "    total_time_no_dict += end - start                          # step 6.4\n",
    "    \n",
    "total_time_dict = 0                                            # step 7\n",
    "for id in ids:                                                 # step 8\n",
    "    start = time.time()                                        # step 8.1\n",
    "    inventory.get_laptop_from_id_fast(id)                      # step 8.2\n",
    "    end = time.time()                                          # step 8.3\n",
    "    total_time_dict += end - start                             # step 8.4\n",
    "    \n",
    "print(total_time_no_dict)                                      # step 9\n",
    "print(total_time_dict)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Two Laptop Promotion"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "import csv                            \n",
    "\n",
    "class Inventory():                    \n",
    "    \n",
    "    def __init__(self, csv_filename):\n",
    "        with open(csv_filename) as f: \n",
    "            reader = csv.reader(f)\n",
    "            rows = list(reader)\n",
    "        self.header = rows[0]        \n",
    "        self.rows = rows[1:]\n",
    "        for row in self.rows:              \n",
    "            row[-1] = int(row[-1])\n",
    "        self.id_to_row = {}                        \n",
    "        for row in self.rows:                       \n",
    "            self.id_to_row[row[0]] = row \n",
    "    \n",
    "    def get_laptop_from_id(self, laptop_id):\n",
    "        for row in self.rows:                 \n",
    "            if row[0] == laptop_id:\n",
    "                return row\n",
    "        return None   \n",
    "    \n",
    "    def get_laptop_from_id_fast(self, laptop_id):  \n",
    "        if laptop_id in self.id_to_row:           \n",
    "            return self.id_to_row[laptop_id]\n",
    "        return None\n",
    "\n",
    "    def check_promotion_dollars(self, dollars):    # step 1\n",
    "        for row in self.rows:                      # step 2\n",
    "            if row[-1] == dollars:\n",
    "                return True\n",
    "        for row1 in self.rows:                     # step 3\n",
    "            for row2 in self.rows:\n",
    "                if row1[-1] + row2[-1] == dollars:\n",
    "                    return True\n",
    "        return False                               # step 4"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "True\n",
      "False\n"
     ]
    }
   ],
   "source": [
    "inventory = Inventory('laptops.csv')               # step 5\n",
    "print(inventory.check_promotion_dollars(1000))     # step 6\n",
    "print(inventory.check_promotion_dollars(442))      # step 7"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Optimizing Laptop Promotion"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "import csv                            \n",
    "\n",
    "class Inventory():                    \n",
    "    \n",
    "    def __init__(self, csv_filename):\n",
    "        with open(csv_filename) as f: \n",
    "            reader = csv.reader(f)\n",
    "            rows = list(reader)\n",
    "        self.header = rows[0]        \n",
    "        self.rows = rows[1:]\n",
    "        for row in self.rows:              \n",
    "            row[-1] = int(row[-1])\n",
    "        self.id_to_row = {}                        \n",
    "        for row in self.rows:                       \n",
    "            self.id_to_row[row[0]] = row\n",
    "        self.prices = set()                          # step 1\n",
    "        for row in self.rows:                        # step 2\n",
    "            self.prices.add(row[-1])\n",
    "    \n",
    "    def get_laptop_from_id(self, laptop_id):\n",
    "        for row in self.rows:                 \n",
    "            if row[0] == laptop_id:\n",
    "                return row\n",
    "        return None   \n",
    "    \n",
    "    def get_laptop_from_id_fast(self, laptop_id):  \n",
    "        if laptop_id in self.id_to_row:           \n",
    "            return self.id_to_row[laptop_id]\n",
    "        return None\n",
    "\n",
    "    def check_promotion_dollars(self, dollars):    \n",
    "        for row in self.rows:                   \n",
    "            if row[-1] == dollars:\n",
    "                return True\n",
    "        for row1 in self.rows:                  \n",
    "            for row2 in self.rows:\n",
    "                if row1[-1] + row2[-1] == dollars:\n",
    "                    return True\n",
    "        return False                        \n",
    "    \n",
    "    def check_promotion_dollars_fast(self, dollars): # step 3\n",
    "        if dollars in self.prices:                   # step 4\n",
    "            return True\n",
    "        for price in self.prices:                    # step 5\n",
    "            if dollars - price in self.prices:\n",
    "                return True\n",
    "        return False                                 # step 6"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "True\n",
      "False\n"
     ]
    }
   ],
   "source": [
    "inventory = Inventory('laptops.csv')                 # step 7\n",
    "print(inventory.check_promotion_dollars_fast(1000))  # step 8\n",
    "print(inventory.check_promotion_dollars_fast(442))   # step 9"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Comparing Performance"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0.7781209945678711\n",
      "0.0003719329833984375\n"
     ]
    }
   ],
   "source": [
    "prices = [random.randint(100, 5000) for _ in range(100)] # step 1\n",
    "\n",
    "inventory = Inventory('laptops.csv')                     # step 2\n",
    "\n",
    "total_time_no_dict = 0                                   # step 3\n",
    "for price in prices:                                     # step 4\n",
    "    start = time.time()                                  # step 4.1\n",
    "    inventory.check_promotion_dollars(price)             # step 4.2\n",
    "    end = time.time()                                    # step 4.3\n",
    "    total_time_no_dict += end - start                    # step 4.4\n",
    "    \n",
    "total_time_dict = 0                                      # step 5\n",
    "for price in prices:                                     # step 6\n",
    "    start = time.time()                                  # step 6.1\n",
    "    inventory.check_promotion_dollars_fast(price)        # step 6.2\n",
    "    end = time.time()                                    # step 6.3\n",
    "    total_time_dict += end - start                       # step 6.4\n",
    "    \n",
    "print(total_time_no_dict)                                # step 7\n",
    "print(total_time_dict)"
   ]
  }
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