medium Object-Oriented Programming

Bank Account with Validation

The Brief

Meridian Banking's core ledger microservice needs a robust account class. The previous implementation let balances go negative silently — causing audit failures. Rebuild the class with proper encapsulation so invalid operations raise exceptions rather than corrupting state.

Acceptance Criteria

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4 Provide a read-only balance property (no setter)

1 Define a class BankAccount with private balance (prefix with underscore)

2 Implement deposit(amount) — must raise ValueError if amount is non-positive

3 Implement withdraw(amount) — must raise ValueError for non-positive or insufficient funds

5 Demonstrate handling a successful deposit, a successful withdraw, and a caught exception

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solution.py

Python 3

# Meridian Banking — BankAccount with encapsulation

class BankAccount:
    def __init__(self, holder, opening_balance=0):
        pass  # TODO

    # TODO: deposit method

    # TODO: withdraw method

    # TODO: balance property


# TODO: demonstrate deposit, withdraw, and handling a caught exception

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