Question

Python Programming

This assignment will give you practice with interactive programs, if/else statements, collections, loops and functions.

Problem Description
A small car yard dealing in second hand cars needs an application to keep records of cars in stock. Details of each car shall include registration(rego), model, color, price paid for the car (i.e. purchase price) and selling price. Selling price is calculated as purchased price plus mark-up of 30%. For example, Toyota Corolla bought for $20,000 will have the selling price of 20000 * (1 + 0.3) = 26000.

Task Requirements
Imagine you have been invited to develop a menu driven python application to manage records of cars in stock. Based on the problem description, starter program (code template) has been provided. Investigate the provided starter program. There are four scripts(application.py, caryard.py, cars.py and vehicle.py). Driver function(main) is defined in the appliction.py, which imports caryard module(caryard.py). Caryard declares all the core functions (buy, sell, search, etc. …) for supporting the car yard business. The caryard module imports cars module(cars.py), and the cars module in turn imports the vehicle that include a definition of a Car class.
Program is executed by loading and running the application.py. The important work of interconnecting and wiring of modules and functions have been already been done. However, most of these functions, although declared and wired up in the program are not yet implemented. Your task is to implement these functions. There are eleven (11) tasks to be completed described next within the modules:

1. application.py
• Task 1: implement menu ()

2. caryard.py
• Task 2: implement buy_car ()
• Task 3: implement sell_car ()
• Task 4: implement search_car ()
• Task 5: implement list_all_cars ()

3. cars.py
• Task 6: implement addCar (rego, model, color, price)
• Task 7: implement removeCar (rego)
• Task 8: implement all_cars ()
• Task 9: implement search(rego)

4. vehicle.py
• Task 10: implement the Car class
• Task 11: UML model of a Car class

Description of Program functions:

Program displays a menu on execution. Five menu options are available to allow the user to buy, sell, search, show all cars, and exit program respectively. Program functionality and screen output for each of the menu option when selected by the user follows:

Program menu on execution:



Option 1 (Buy a car): User enters 1. Note the error message for duplicate car rego

 
Option 2 (Sell a car): User enters 2. Note the error message for invalid car rego, and the sell price which is a (30%) mark-up of purchase price.

Option 3 (Search): User enters 3

Option 4 (Show all): User enters 4

Option 5 (Exit Program): User enters 5

Answer 1

'''

Python version : 2.7

Python program to create a car class

'''

class Car:

              

               def __init__(self, rego, model, color, purchase_price):

                              self.rego = rego

                              self.model = model

                              self.color = color

                              self.purchase_price = purchase_price

                              self.selling_price = self.purchase_price*(1+0.3)

                             

               def __str__(self):

                              return('Registration : %s Model: %s Color : %s Purchase Price : $%.2f Selling Price : $%.2f' %(self.rego, self.model, self.color, self.purchase_price, self.selling_price))

                             

               def __repr__(self):

                              return('Registration : %s Model: %s Color : %s Purchase Price : $%.2f Selling Price : $%.2f' %(self.rego, self.model, self.color, self.purchase_price, self.selling_price))

                             

               def get_rego(self):

                              return self.rego

                             

               def get_model(self):

                              return self.model

                             

               def get_color(self):

                              return self.color

                             

               def get_purchase_price(self):

                              return self.purchase_price

                             

               def get_selling_price(self):

                              return self.selling_price

                             

               def set_rego(self, rego):

                              self.rego = rego

                             

               def set_model(self):

                              self.model = model

                             

               def set_color(self,color):

                              self.color = color

                             

               def set_purchase_price(self,purchase_price):

                              self.purchase_price = purchase_price

                              self.selling_price = self.purchase_price(1+0.3)

                             

#end of vehicle.py                          

Code Screenshot:

'''

Python version : 2.7

Python program to create functions to manage the list of cars

'''

from vehicle import Car

def addCar(rego, model, color, price, carList):

              

               idx = search(rego,carList)

              

               if(idx == -1):

                              carList.append(Car(rego,model,color,price))

                              return True

                             

               return False

                             

def removeCar(rego,carList):

              

               idx = search(rego,carList)

              

               if(idx != -1):

                              car = carList.pop(idx)

                              return car

               else:

                              return None

                             

def all_cars(carList):

               if(len(carList) == 0):

                              print('No cars present')

               else:      

                              for car in carList:

                                             print(car)

                             

def search(rego,carList):

              

               for i in range(len(carList)):

                             

                              if carList[i].get_rego() == rego:

                                             return i

                                            

               return -1                            

#end of cars.py

Code Screenshot:

'''
Python version : 2.7
Python program to create menu options for the main
'''

import cars

def buy_car(carList):
  
   rego = raw_input('Registration number : ')
   model = raw_input('Model : ')
   color = raw_input('Color : ')
   purchase_price = float(raw_input('Purchase price : $'))
  
   if(cars.addCar(rego,model,color,purchase_price,carList)):
       print('Car with registration : %s already exists' %(rego))
  
def sell_car(carList):
  
   rego = raw_input('Registration Number : ')
   car = cars.removeCar(rego,carList)
   if(car == None):
       print("Car with registration : %s doesn't exists" %(rego))
   else:
       print("Car sold at price : %.2f" %(car.get_selling_price()))
      
def search_car(carList):
  
   rego = raw_input('Registration Number : ')
   idx = cars.search(rego,carList)
  
   if(idx != -1):
       print(carList[idx])
   else:
       print("Car with registration : %s doesn't exists" %(rego))
      
def list_all_cars(carList):
          
   cars.all_cars(carList)
  
#end of caryard.py      

Code Screenshot:

'''

Python version : 2.7

Python program to create the main application

'''

import caryard

def main():

               carList = []

               choice = 1

               while choice != 5:

                              print('1. Buy a Car')

                              print('2. Sell a Car')

                              print('3. Search for a Car')

                              print('4. Show all cars')

                              print('5. Exit')

                             

                              choice = int(raw_input('Enter your choice : '))

                             

                              if choice == 1:

                                             caryard.buy_car(carList)

                              elif choice == 2:

                                             caryard.sell_car(carList)

                              elif choice == 3:

                                             caryard.search_car(carList)

                              elif choice == 4:

                                             caryard.list_all_cars(carList)

                              elif choice != 5:

                                             print('Invalid choice')

                              print('')

               print('Bye!')

main()   

#end of application.py                                 

Code Screenshot:

Output:

Car UML: