> =======================================
> class BankAccount(object):
> def __init__(self, initial_balance=0):
> self.balance = initial_balance
> def deposit(self, amount):
> self.balance += amount
> def withdraw(self, amount):
> self.balance -= amount
> def overdrawn(self):
> return self.balance < 0
> my_account = BankAccount(15)
> my_account.withdraw(5)
> print my_account.balance
> =========================================
>
> This prints the expected "10".
>
> My question is, of what use can "overdrawn" be put? If I change the
> withdrawal amount to 25, it prints the expected "-10", whether the class
> contains the "overdrawn" function or not.
>
> Thanks,
>
> Dick Moores
A very good question. Now I have one for you. What does your bank do when
you try to withdraw money? First, it checks to see if you have the money in
your account. If you do, it subtracts that out of your balance. Whoever
wrote that code failed to do the check within the withdraw function.
=======================================
class BankAccount(object):
def __init__(self, initial_balance=0):
self.balance = initial_balance
def deposit(self, amount):
self.balance += amount
def withdraw(self, amount):
if self.overdrawn():
raise "Insufficient Funds Error"
self.balance -= amount
def overdrawn(self):
return self.balance < 0
my_account = BankAccount(15)
my_account.withdraw(5)
print my_account.balance
=========================================
JS
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
