# Chapter 30 example: a BankAccount whose methods guard the balance.
class Account:
    def __init__(self, owner):
        self.owner = owner
        self.balance = 0

    def deposit(self, amount):
        if amount > 0:
            self.balance = self.balance + amount

    def withdraw(self, amount):
        if amount > 0 and amount <= self.balance:
            self.balance = self.balance - amount
            return True
        return False

    def get_balance(self):
        return self.balance


acc = Account("Keiko")
acc.deposit(100)
acc.withdraw(30)
print(acc.get_balance())   # 70
# TODO: add a .can_afford(amount) method that returns True when the
# balance is at least amount, and use it before withdrawing.