Section 1/3Class Design Overview

Class Design Overview

Bank aggregates accounts (holds a list of references, does not own them).

Project: Bank System

Build a mini banking system from scratch using the OOP skills you have learned. This project brings together inheritance, encapsulation, accessors, aggregation, and dunder methods in one realistic application.

Class Design Overview

┌──────────────────────────┐
│       BankAccount        │
├──────────────────────────┤
│ # _owner                 │
│ # _balance               │
├──────────────────────────┤
│ + deposit(amount)        │
│ + withdraw(amount)       │
│ + get_balance()          │
│ + __str__()              │
└────────────┬─────────────┘
             ↓ inherits
┌──────────────────────────┐
│     SavingsAccount       │
├──────────────────────────┤
│ # _interest_rate         │
├──────────────────────────┤
│ + apply_interest()       │
│ + __str__()              │
└──────────────────────────┘

Bank aggregates accounts (holds a list of references, does not own them).

# PROJECT: Bank System
#
# Build a mini bank system using OOP.
# Requirements:
#   1. BankAccount — base class
#      - __init__(self, owner, balance=0)
#      - deposit(self, amount)  — validated: amount must be > 0
#      - withdraw(self, amount) — validated: cannot exceed balance
#      - get_balance(self)      — accessor
#      - __str__(self)          — e.g. "Alice: £500"
#
#   2. SavingsAccount(BankAccount) — inherits from BankAccount
#      - __init__(self, owner, balance=0, interest_rate=0.05)
#      - apply_interest(self)  — adds balance * interest_rate to balance
#      - __str__(self)         — e.g. "Alice (Savings, 5.0%): £500"
#
#   3. Bank — aggregates accounts
#      - __init__(self, name)
#      - add_account(self, account)
#      - get_account(self, owner) — return account by owner name (or None)
#      - total_deposits(self)     — sum of all account balances
class BankAccount:
    def __init__(self, owner, balance=0):

Output:

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Project: Bank System

Class Design Overview

Hints

Your Task

Class Design Overview

Project: Bank System

Class Design Overview

Hints

Your Task

Output: