Getting your Hands Dirty with Python

This is an endeavor from my side to demonstrate how easy to grasp language Python is. Targeted for developers with some knowledge of programming.

Real Time Use Case - Food Order & Billing

Check booking data for availability of tables in a restaurant, takes the customer order and generates the bill to the customer and finally gets the rating of the service from the customer

Key Features covered in the program

§  Classes / Objects

§  Docstrings

§  File Handling

§  Error and Exception Handling

§  Data Structures – Dictionaries

§  lambda Function

§  String Manipulation

Imports from Standard Library

Classes & Objects

Docstrings

Read File

Exception Handling

Dictionaries

lambda Function

String Manipulation

Source Code

# Imports from standard library

import datetime

import time

import sys

print("WELCOME TO QUICKCONNECT HUB")

class Restaurant:

    order = {}

    total = 0.0

    tax = 0.04

    def __init__(self):

        """ Read / Display restaurant table booking information stored in a file """

        print("\n" "Displaying Table Booking Data ...." "\n")

        time.sleep(2)

               

        try:

           with open("table.txt","r") as tabfile:

               for line in tabfile:

                  print(line)

               time.sleep(2)

               print("\n" "Please occupy empty table")

               time.sleep(2)

        except FileNotFoundError:

           print("The data file is missing")

           sys.exit()

    def menuDisplay(self):

        """ Display the items in the menu for selection """

       

        print("\n" "Select the items from menu")

        print("\n" "********** MENU CARD **********")

        print("ITEM \t\t PRICE")

        self.menu = {"Burger":120, "Pizza":200, "Hotdog":150,

                "Parata":50, "Donut":80, "Nugget":50,

                "Paneer":120, "Pakora":80, "Coffee":25}

        for k,v in self.menu.items():

              print(k,":", "\t",  "Rs",v)

    def orderConfirm(self):

        """ Take the order and display the items for confirmation """

        print("\n" "Please let us know the order")

        time.sleep(2)

        for i in range(len(self.menu)):

           

            self.select_item = input("\n" "Select an Item: ")

            if self.select_item not in self.menu:

                print("Selected item is not available in the menu")

                self.select_item = input("Please re-enter an item: ")

               

            try:

                self.quantity = int(input("Enter the Quantity: "))

                self.order[self.select_item] = self.quantity

            except Exception:

                print("Quantity to be entered as Numeric")

                self.quantity = int(input("Please re-enter the Quantity:"))

                self.order[self.select_item] = self.quantity

            self.item_flag = input("\n" "Do you wish to continue?(Y/N)")

            if self.item_flag == "N":

                break

           

        print("\n" "Please confirm the order given:")

        print(self.order)

        print("\n" "THANK YOU! Please wait while we get your items")

        time.sleep(2)

        print("\n" "Here you go, Please have your order")

        time.sleep(2)

    def billGeneration(self):

        """ Generates bill for the ordered items """

       

        print("\n" "Generating Bill....")

        time.sleep(2)

        print("------------------------------------------")

        current_time = datetime.datetime.now()

        print("Invoice Generated On:", current_time.strftime("%Y-%m-%d %H:%M:%S"))

        print("------------------------------------------")

        for key in self.menu.keys():

           if key in self.order:

              print(key, "\t", "Qty", self.order[key], "\t", "Rs", self.menu[key] * self.order[key])

              self.cost_item = self.menu[key] * self.order[key]

              self.total += self.cost_item

        self.taxamt = lambda amt, tax : amt * tax

        print("------------------------------------------")

        print("TOTAL:", "\t", "\t", "Rs", self.total)

        print("GST 4%", "\t", "\t", "Rs", self.taxamt(self.total, self.tax))

        print("------------------------------------------")

        self.total += self.taxamt(self.total, self.tax)

        print("GRAND TOTAL:", "\t", "Rs", self.total)

        print("------------------------------------------")

       

    def rateService(self):

        """ Display customer ratings of the services provided """

       

        print("\n" "Dear customer, Please Rate our Service * * * * * ")

        rating = input("\n" "Please key-in the Stars : ")

        rating = rating.replace(" ","")

       

        if rating == "*":

            print("Service Rated is:", rating, " TERRIBLE")

        elif rating == "**":

            print("Service Rated is:", rating, " BAD")

        elif rating == "***":

            print("Service Rated is:", rating, " OK")

        elif rating == "****":

            print("Service Rated is:", rating, " GOOD")

        elif rating == "*****":

            print("Service Rated is:", rating, " EXCELLENT")

       

        print("\n" "THANK YOU! PLEASE VISIT AGAIN....")

       

       

#Main Program 

res = Restaurant()

res.menuDisplay()

res.orderConfirm()

res.billGeneration()

res.rateService()

Table Data File

Output

I really hope the above walk-through help in getting view of python programming.