ATM Design

• Bank Class

  • Has the Bank constructor, which generates a bank
  • Card_nums and pins can be added to the bank with add_entry() method
  • add_account() only works for existing card_nums, program will do nothing if it doesn't exist
  • check_pin() takes card_num and pin_num to verify, this ensures ATM doesn't receive pin from Bank
  • update_account() is used by ATM to change balances

• ATM Class

  • Constructor takes in a Bank obj and cash_bin
  • swipe() methods takes in card_num and pin to check if valid.
  • A proper user interface would call this method after invoking user input for pin.
  • account_select() lets user select their account if valid pin was entered
  • account_actions() method is the way balance/withdraw/deposit are implemented.
  • call function is the very basic driver of the ATM.
    • It is a driver of ATM, that runs through a list of actions and returns messages
    • This is useful for testing
    • A user interface would behave similarly logic-wise (only entering actions after valid pin, etc), but would await user input
    • Another engineer can see from this function how to go about using swipe(), account_selection(), and account_actions()

Testing the Program

This program can be tested by simply running:

python3 test_ATM.py

in the command line