bank_inheritance.py

class BankAccount:
  def __init__(self, interest_rate=.02):
    self.balance = 0
    self.interest_rate = interest_rate
    
  def deposit(self, amount):
    if amount < 0:
      return False
    self.balance += amount
    return self.balance
    
  def withdraw(self, amount):
    if amount < 0:
      return False
    self.balance -= amount
    return amount
  
  def accumulate_interest(self):
    self.balance += self.balance * self.interest_rate
    
class ChildrensAccount(BankAccount):
  def __init__(self):
    self.interest_rate = 0
    super().__init__(self.interest_rate)
    
  def accumulate_interest(self):
    self.balance += 10
    
class OverdraftAccount(BankAccount):
  def __init__(self, interest_rate=.02, overdraft_penalty=40):
    super().__init__(interest_rate)
    self.overdraft_penalty = overdraft_penalty

  def withdraw(self, amount):
    if amount > self.balance:
      self.balance -= self.overdraft_penalty
      return False

    # use the inherited withdraw method if the user
    # has enough money.
    return super().withdraw(amount)

  def accumulate_interest(self):
    if (self.balance <= 0):
      return False

    return super().accumulate_interest()

basic_account = BankAccount()
basic_account.deposit(600)
print("Basic account has ${}".format(basic_account.balance))
basic_account.withdraw(17)
print("Basic account has ${}".format(basic_account.balance))
basic_account.accumulate_interest()
print("Basic account has ${}".format(basic_account.balance))
print()

childs_account = ChildrensAccount()
childs_account.deposit(34)
print("Child's account has ${}".format(childs_account.balance))
childs_account.withdraw(17)
print("Child's account has ${}".format(childs_account.balance))
childs_account.accumulate_interest()
print("Child's account has ${}".format(childs_account.balance))
print()

overdraft_account = OverdraftAccount()
overdraft_account.deposit(12)
print("Overdraft account has ${}".format(overdraft_account.balance))
overdraft_account.withdraw(17)
print("Overdraft account has ${}".format(overdraft_account.balance))
overdraft_account.accumulate_interest()
print("Overdraft account has ${}".format(overdraft_account.balance))