Task:

Your task is to design a simple interactive inventory management system using Python functions.

Question:

You are asked to build a simple inventory management system for storing and updating information about a company's products. To simplify, assume that this company has only three products. For each product, the system stores a record about its inventory level (number of items) and the price of each item. Note that this information will need to be initialized before running the program.

There are three main operations provided by the system (listed below). When the system is started, the program should list these three operations and let the users choose which one to execute. These functionalities are as follows:

1) Generate overall statistics for the entire inventory (total number of items, average price per item, the minimum number of items among the products and the maximum number of items among the products).

2) Retrieve information (quantity or price) for a given product

3) Update information (quantity or price) for a given product

Once the user makes a selection, the program should invoke a relevant function and complete the operation. The system should continue running (i.e., functionality selection should be provided to the user repeatedly) until the user kills the execution of the program (possibly with a unique input character). One possible system design could have four functions:

Function 1: display_system_operations
Inputs: None
Outputs: None
Description: This function prints out all possible operations of the system for the user to choose.

Function 2: generate_overall_stats
Inputs: None
Outputs: Print overall statistics
Description: This function generates all basic statistics of all products, such as the total number of items, average price per item, the minimum number of items among the products and the maximum number of items among the products.

Function 3: retrieve_information
Inputs: product name and information type (quantity or price or both)
Outputs: Print the information requested
Description: This function retrieves the relevant information for a given product, which is obtained from the user as an input.

Function 4: update_information
Inputs: product name, information type (quantity or price) and the updated quantity or price
Outputs: None
Description: This function updates the quantity or price information in the inventory.

Hints:

1) You can initialize the product quantities and the prices using lists. For indexing the products, you can use a list of lists.
2) Remember that lists can be modified directly; the important thing is to identify the correct indices based on user input.
3) You can use formatting options (the format method) to print out nicer looking outputs.
4) You can design a main function which will be the starting point when you execute the entire program. Main function is also a function like others.

Using python