Python 8.20 Develop a class BankAccount that supports these methods: _ _init_ _(

Question

Python 8.20 Develop a class BankAccount that supports these methods:

_ _init_ _(): Initializes the bank account balance to the value of the input argument, or to 0 if no input argument is given.

withdraw(): Takes an amount as input and withdraws it from the balance.

deposit(): Takes an amount as input and adds it to the balance.

balance(): Returns the balance on the account.

Example:

>>> x = BankAccount(700)

>>> x.balance()

700.00

>>> x.withdraw(70)

>>> x.balance()

630.00

>>> x.deposit(7)

>>> x.balance()

637.00

8.40 In Problem 8.20, there are some problems with the implementation of the class BankAccount, and they are illustrated here:

>>> x = BankAccount(-700)

>>> x.balance()

-700

>>> x.withdraw(70)

>>> x.balance()

-770

>>> x. deposit(-7)

>>> x.balance()

Balance: -777

The problems are: (1) a bank account with a negative balance can be created, (2) the withdrawal amount is greater than the balance, and (3) the deposit amount is negative. Modify the code for the BankAccount class so that a ValueError exception is thrown for any of these violations, together with an appropriate message: 'Illegal balance', 'Overdraft', or 'Negative deposit'.

Example:

>>> x = BankAccount2(-700)

Traceback (most recent call last):

...

ValueError: Illegal balance

Explanation / Answer

working python code for first part.

# your code goes here
class BankAccount:
def __init__(self, init_bal):
   """Creates an account with the given balance."""
   self.init_bal = init_bal
   self.account = init_bal

def deposit(self, amount):
   """Deposits the amount into the account."""
   self.amount = amount
   self.account += amount

def withdraw(self, amount):
   self.account -= amount
  
def balance(self):
print self.account
  
x = BankAccount(700)
x.balance()
x.withdraw(70)
x.balance()
x.deposit(7)
x.balance()

output:

700

630

637

working python code for part 2

# your code goes here
class BankAccount:
def __init__(self, init_bal):
   if(init_bal >=0):
       self.init_bal = init_bal
       self.account = init_bal
   else:
       raise ValueError('a bank account with a negative balance can be created')

def deposit(self, amount):
   """Deposits the amount into the account."""
   self.amount = amount
   self.account += amount

def withdraw(self, amount):
   if(amount>=0):
       self.account -= amount
   else:
       raise ValueError('Negative value')

  
def balance(self):
print self.account
  
x = BankAccount(-5)

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