Clean Up Rewards Points System

[constanceshi]

Changes to rewardsPointsSystem.py:

• move import statement to the top of the code
• change argument in item constructor to follow word_underscore naming convention (same as other variables)
• assign a constant variable REWARDS_RATIO_ABOVE_THRESHOLD to 17 instead of using magic numbers
• add an error log attribute to the rewards system
• use log_entry properties via dot notation rather than array access
• initialize rewards points to 0 if not present
• if the log entry is not present, add the log to the error log and do not execute the rest of the for loop for this log entry
• remove resetting of items purchased and raising a value error and instead use the above approach to append the log to the error list
• remove multiplication of item id by item price when accumulating total spent
• increment the dictionary counting the number of each item purchased by 1 instead of the item's id
• only loop through items in items_purchased once, keeping the total_spent regardless of the customer and incrementing the dictionary keeping count of how many of each item is purchased
• move the rewards points subtraction and amount_spent update into a loop that only runs if the customer has an id
• remove print statement
• loop through the rewards points customers by getting them from amount_spent.keys()
• compare amount_spent[customer_id] to rewards_cutoff instead of just amount_spent (a dictionary)
• use an if else loop in adding rewards points for customers rather than setting it twice if they have spent over the cutoff

Issues

Proposes changes addressing #1