Computer Science 111 – Fundamentals of Programming I
Programming Project 10
Due date: 12 Noon, Friday, December 4 (Tuesday labs)
12 Noon, Monday, December 8 (Thursday lab)
In this project, you will read and modify some Python classes. All of the files that you
need are in the project10 directory in Handouts.
Part I
The file bank.py contains the SavingsAccount and Bank classes discussed in lectures.
Open bank.py with IDLE and review the code for the SavingsAccount class and the
testAccount function. Press function-5 to load the module into the shell and notice the
outputs.
The methods deposit and withdraw work fine if the amount argument is valid, but
produce erroneous results otherwise. Your job in this first part is to fix these methods so
that they return the appropriate error messages if the amount argument is invalid. You
should see these messages displayed in the shell when you run the program again.
Part II
Open bank.py with IDLE and review the code for the Bank class and the createBank
function. Comment out the call of testAccount in the main function and press
function-5 to load the module into the shell. Then run the following lines of code in the
shell:
bank = createBank(10)
print(bank)
bank.computeInterest()
print(bank)
bank.getKeys()
Now try to get an account from the bank, using its get method with the name and pin of
a customer contained therein. Make a deposit into this account, and then print the bank
again, to verify the update to its state. Finally, try to remove this account by running the
bank’s remove method.
2
Note that getKeys returns an empty list. This method and the remove method are
unfinished in the Bank class. Your job in this part is to complete these two methods and
test them to verify that they work correctly.
Part III
Open bank.py with IDLE and uncomment the code in the main function below the call
of testAccount. Press function-5 to load the module into the shell and note the
outputs. Then run the following lines of code in the IDLE shell:
bank = createBank(10)
print(bank)
bank.save("bank.dat")
Check your current working directory to verify that it now contains the bank.dat file.
Try to open it with gedit and view its contents. This is a file of account objects, as
discussed in lecture. Now, return to the IDLE shell and run
main(fileName = "bank.dat")
This should now load the file into a new Bank object and print its contents. Finally, read
carefully the code for the __init__ and save methods in the Bank class.
Part IV
Open atm.py with IDLE and study the code for the ATM class and the main function
carefully. This module runs a GUI-based ATM application. Press function-5 to load the
module into the shell and note the outputs. Try logging in with the credentials of an
existing account, logging out, and logging in with a different account. Then close the
window and run
main("bank.dat")
This should open the ATM on the bank that you saved in Part III.
Now return to the code for the ATM class and note that the methods getBalance,
deposit, and withdraw have yet to be completed. That’s your job in this part; be sure
to run the program again to test these methods thoroughly (including the error conditions
on the inputs).
3
Part IV (Extra credit: 10 points)
Open bankmanager.py with IDLE and study the code for the BankManager class and
the main function carefully. This module runs a GUI-based application to manage the
bank. Press function-5 to load the module into the shell. Then run
main("bank.dat")
to load the bank from previous sessions.
Try navigating through the accounts, updating an account with a new balance, removing
an account or two, and computing interest.
Management would like you to add a new button called Find account to the user
interface. When the user clicks this button, the application pops up consecutive prompter
boxes for the name and pin (consult the breezypythongui site for details on prompter
boxes). The application then creates a key from these data and attempts to find the index
of the key in the bank’s list of keys. If successful, the application uses the index to
navigate to the desired account and update the view with its information. Otherwise, the
application displays “No such account” in the status field.
Turn in your project10 directory.