Programming Assignment 2 (Shopping)

Write a Python program (Shopping.py) that reads data from multiple data files stored within a folder whose name will be provided in the command line. The program should processes the data to provide answers to questions about the data.

Input data

The following is a sample content of one of these files: 
mirage:p2 raj$ more invoices/1.dat
1,SV Stores,Srivatsan
Carrots,Vegetables/Food,1.5,50
Soap,Toiletries,4,32
Tomatoes,Vegetables/Food,2,40
Bananas,Vegetables/Food,8,8
Socks,Footwear/Apparel,3,56
Curd,Dairy/Food,0.5,32
Milk,Dairy/Food,1.5,24
mirage:p2 raj$
The data in the file describes a shopping bill or invoice. The first line has a unique bill number, the name of the store, and the name of the customer. Subsequent lines in the file (of which there will be at least one) contain details about items purchased. Each subsequent line contains name of item, category of item, quantity purchased, and unit price of item. Sample data folder is available at invoices. A larger data set is available at invoices.zip.

Data Structure

The data should be read and stored in a list with the following structure: 
[('1', 'SV Stores', 'Srivatsan', 
  [('Carrots', 'Vegetables/Food', 1.5, 50.0), 
   ('Soap', 'Toiletries', 4.0, 32.0), 
   ('Tomatoes', 'Vegetables/Food', 2.0, 40.0), 
   ('Bananas', 'Vegetables/Food', 8.0, 8.0), 
   ('Socks', 'Footwear/Apparel', 3.0, 56.0), 
   ('Curd', 'Dairy/Food', 0.5, 32.0), 
   ('Milk', 'Dairy/Food', 1.5, 24.0)
  ]
 ), 

 ('2', 'Big Bazaar', 'Sudeep', 
  [('Baked Beans', 'Canned/Food', 1.0, 125.0), 
   ('Chicken Wings', 'Meat/Food', 0.5, 600.0), 
   ('Cocoa Powder', 'Canned/Food', 1.0, 160.0), 
   ('Capsicum', 'Vegetables/Food', 0.8, 180.0), 
   ('Tie', 'Apparel', 2.0, 390.0), 
   ('Clips', 'Household', 0.5, 32.0)
  ]
 ), 

 ('3', 'Sun General', 'Srivatsan', 
  [('Batteries', 'Utilities', 6.0, 14.0), 
   ('USB Cable', 'Electronics', 1.0, 85.0), 
   ('Ball Pens', 'Stationery', 5.0, 12.0), 
   ('Onions', 'Vegetables/Food', 1.25, 100.0)
  ]
 ), 

 ('4', 'SV Stores', 'Akshaya', 
  [('Face Wash', 'Toiletries', 1.0, 89.0), 
   ('Shampoo', 'Toiletries', 1.0, 140.0), 
   ('Onions', 'Vegetables/Food', 1.0, 98.0), 
   ('Bananas', 'Fruits/Food', 4.0, 8.0), 
   ('Milk', 'Dairy/Food', 1.0, 24.0), 
   ('Biscuits', 'Packed/Food', 2.0, 22.0), 
   ('Maggi', 'Packed/Food', 1.0, 85.0), 
   ('Horlicks', 'Packed/Food', 1.0, 270.0), 
   ('Chips', 'Packed/Food', 1.0, 20.0), 
   ('Chocolates', 'Packed/Food', 4.0, 10.0), 
   ('Cereal', 'Packed/Food', 1.0, 220.0), 
   ('Handwash', 'Toiletries', 1.0, 139.0), 
   ('Air Freshener', 'Toiletries', 2.0, 70.0)
  ]
 ), 

 ('5', 'Big Bazaar', 'Akshaya', 
  [('Trousers', 'Women/Apparel', 2.0, 870.0), 
   ('Shirts', 'Women/Apparel', 1.0, 1350.0), 
   ('Detergent', 'Household', 0.5, 270.0), 
   ('Tee Shirts', 'Women/Apparel', 4.0, 220.0), 
   ('Instant Noodles', 'Canned/Food', 3.0, 23.0)
  ]
 )
]

Menu

After reading, the program prompts the user with a menu of 6 options:
  1. See all customers
  2. See all stores
  3. See all categories
  4. See customer purchases at various stores for a given customer
  5. See loyal customers - customers who purchase only from one store
  6. Quit

Modular design using functions

You should modularize the program by defining several functions, such as the following: 
read_data() - this function reads data and returns the list of data as described earlier
get_all_customers()
get_all_stores()
get_all_categories()
customer_spend_per_store() - given a customer, returns list of expenditure per store for that customer
loyal() - returns loyal customers

Sample run

ASCSC1PP629W1:p2 raj$ python3 Shopping.py invoices

Welcome to Shopping Program

See all customers (c)
See all stores (s)
See all categories (g)
See customer purchases at various stores (p cname)
See loyal customers (y)
Quit (q)

What do you want to see? c

Customers:

Akshaya
Srivatsan
Sudeep


See all customers (c)
See all stores (s)
See all categories (g)
See customer purchases at various stores (p cname)
See loyal customers (y)
Quit (q)

What do you want to see? s

Stores:

Big Bazaar
SV Stores
Sun General


See all customers (c)
See all stores (s)
See all categories (g)
See customer purchases at various stores (p cname)
See loyal customers (y)
Quit (q)

What do you want to see? g

Categories:

Apparel
Canned/Food
Dairy/Food
Electronics
Footwear/Apparel
Fruits/Food
Household
Meat/Food
Packed/Food
Stationery
Toiletries
Utilities
Vegetables/Food
Women/Apparel


See all customers (c)
See all stores (s)
See all categories (g)
See customer purchases at various stores (p cname)
See loyal customers (y)
Quit (q)

What do you want to see? w

Invalid command


See all customers (c)
See all stores (s)
See all categories (g)
See customer purchases at various stores (p cname)
See loyal customers (y)
Quit (q)

What do you want to see? p Akshaya


Akshaya spend per store:

Big Bazaar	  4174.0
SV Stores	  1341.0
Sun General	       0


See all customers (c)
See all stores (s)
See all categories (g)
See customer purchases at various stores (p cname)
See loyal customers (y)
Quit (q)

What do you want to see? y

Loyal customers:

Sudeep


See all customers (c)
See all stores (s)
See all categories (g)
See customer purchases at various stores (p cname)
See loyal customers (y)
Quit (q)

What do you want to see? q

Bye!

ASCSC1PP629W1:p2 raj$