PYTHON

Your task this lab is to design, implement and test your own class called BankAccount that models a simple bank account. The bank account has a balance that can be adjusted by deposits and withdrawals. Your class will implement this behavior.

Floating-point numbers are approximate values and can lead to rounding errors. As a result, working with floating-point numbers can yield unexpected results. A more reliable way to work with currency calculations is to use the decimalmodule to work with decimal numbers. Decimal numbers work like a floating-point number, except that they are exact values so that you do not have to worry about the unexpected results that can be introduced by floating -point numbers.

The Program Specification

Write a basic class that simulates a bank account that supports the following options:

• Customers can deposit and withdraw funds.
• If sufficient funds are not available for withdrawal, a $10.00 overdraft penalty is charged.
• Once within a given month, interest can be added to the account. The interest rate can vary every month.

Class BankAccount

Instance Members:

• balance
• last_interest_date

Instance Methods

• constructor - Constructs a bank account with a given balance. Provides the default parameter initial_balance (default balance = Decimal("0.0").
• deposit - Deposits money into the account. Takes the parameter amount to deposit.
• withdraw - Makes a withdrawal from the account or charges a penalty if sufficient funds are not available. Takes the parameter amount to withdraw.
• add_interest - Adds interest once monthly to a positive account balance. Takes the parameter rate that represents the current rate of interest (for allowable rate of interest 1% <= rate <= 2%). Monitor the date and only apply the rate calculation once monthly.
• get_balance - Returns the current account balance.

Input Error Checking: Mutators must validate parameter data before writing to private instance fields. If parameter data is invalid there is no change in state of the bank account.

Testing Specification

Test Run Requirements: Provide a test driver that includes at minimum the following actions in the order as shown below:

• Instantiate a bank account with an original balance of $1000.00
• Deposit $500.00
• Withdraws $2000.00
• Adds 1% interest
• Adds 2% interest
• Deposit $125,000.99
• Withdraws $0.99
• Withdraws $126,500.00
• Withdraws $10.00
• Adds 1% interest

Show the account balance after each action.

Your test driver will need to import your class.

Example:

from yournameBank import BankAccount

Example: Ashley would import her BankAccount class into the test driver as follows:

from ashleyBank import BankAccount

If you need an example, see the Unit 3 Module code examples.

Here are some tips and REQUIREMENTS:

1. Always use self for the first argument to instance methods.

2. Use Decimal values for the balance.

3. Use named constants versus literal values. Note: Use UPPER_UNDER format to define named constants.

Example:

 OVERDRAFT_FEE = Decimal(10.0)

4. Format currency output display values to 2 decimal places. Supply the $ symbol. Reflect negative balances as -$ (i.e. -$10.00). Display thousands separators.

More:

• Be sure that all output is descriptive.
• No user input should be done in this program.

I am not supplying a sample output this week - the above description is adequate.

Deliverables: 2 files to submit:

• Your bank account class file (name this file yournameBank.py) and
• Your class test driver (name this file yournameLab3.py)

Example:

Ashley's bank account class filename would be ashleyBank.py

Ashley's test driver filename would be ashleyLab3.py

Provide a copy of your test run in your test driver file.

Be sure to comment out your run so that your .py file will still run in the grader test bed.

What to Turn In

1. Hand in only one class .py file.

2. Use this title format for your .py file : yournameBank.py (Note: Use YOURname).

3. Hand in only one test driver .py file

4. Name the test driver file yournameLab3.py (Again, use YOUR name).

Submitting multiple files to an assignment

Your lab 3 assignment requires uploading more than one file; you should upload these 2 files as one submission. In this assignment you need to upload 2 .py files (a class file and a test driver) - both part of one assignment submission. To add these files, the Add Another File button is clicked to upload the two files one by one. Check to make sure that both files uploaded okay. When finished click Submit Assignment.