Question

PYTHON

The provided code in the ATM program is incomplete. Complete the run method of the ATM class. The program should display a message that the police will be called after a user has had three successive failures. The program should also shut down the bank when this happens. [comment]: <> (The ATM program allows a user an indefinite number of attempts to log in. Fix the program so that it displays a message that the police will be called after a user has had three successive failures. The program should also shut down the bank when this happens.)

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Atm.py

"""
File: atm.py
Project 8.4

This module defines the ATM class and its application.

Modifies the user interface so that it prints a message and shuts down
if the user fails at three consecutive logins.

Can be modified to run as a script after a bank has been saved.
"""
from bank import Bank, SavingsAccount

class ATM(object):
"""This class represents terminal-based ATM transactions."""

def __init__(self, bank):
self._account = None
self._bank = bank
self._methods = {} # Jump table for commands
self._methods["1"] = self._getBalance
self._methods["2"] = self._deposit
self._methods["3"] = self._withdraw
self._methods["4"] = self._quit

def run(self):
"""Logs in users and processes their accounts."""
failureCount = 0
while True:
# Prompt user to enter name

# Prompt user to enter PIN

# Load account

# If account was not found
# Print "Error, unrecognized PIN"

# If account name does not match name
# Print "Error, unrecognized name"

# If account is valid
# Load account menu

# If an invalid entry was made three times
# Print "Shutting down and calling the cops!" and end program

def _processAccount(self):
"""A menu-driven command processor for a user."""
while True:
print("1 View your balance")
print("2 Make a deposit")
print("3 Make a withdrawal")
print("4 Quit\n")
number = input("Enter a number: ")
theMethod = self._methods.get(number, None)
if theMethod == None:
print("Unrecognized number")
else:
theMethod()
if self._account == None:
break

def _getBalance(self):
print("Your balance is $", self._account.getBalance())

def _deposit(self):
amount = float(input("Enter the amount to deposit: "))
self._account.deposit(amount)

def _withdraw(self):
amount = float(input("Enter the amount to withdraw: "))
message = self._account.withdraw(amount)
if message:
print(message)

def _quit(self):
self._bank.save()
self._account = None
print("Have a nice day!")

# Top-level functions
def main():
"""Instantiate an ATM and run it."""
bank = Bank("bank.dat")
atm = ATM(bank)
atm.run()

def createBank(number = 0):
"""Saves a bank with the specified number of accounts.
Used during testing."""
bank = Bank()
for i in range(number):
bank.add(SavingsAccount('Name' + str(i + 1),
str(1000 + i),
100.00))
bank.save("bank.dat")

# Creates a bank with the following names / PINS:
# Name1, 1000
# Name2, 1001
# Name3, 1002
# Name4, 1003
# Name5, 1004
createBank(5)
main()

------------------------------------------------

bank.py

"""
File: bank.py

This module defines the SavingsAccount and Bank classes.
"""
import pickle

class SavingsAccount(object):
"""This class represents a savings account
with the owner's name, PIN, and balance."""

RATE = 0.02
  
def __init__(self, name, pin, balance = 0.0):
self._name = name
self._pin = pin
self._balance = balance

def __str__(self):
result = 'Name: ' + self._name + '\n'
result += 'PIN: ' + self._pin + '\n'
result += 'Balance: ' + str(self._balance)
return result

def getBalance(self):
return self._balance

def getName(self):
return self._name

def getPin(self):
return self._pin

def deposit(self, amount):
"""Deposits the given amount."""
self._balance += amount
return self._balance

def withdraw(self, amount):
"""Withdraws the given amount.
Returns None if successful, or an
error message if unsuccessful."""
if amount < 0:
return 'Amount must be >= 0'
elif self._balance < amount:
return 'Insufficient funds'
else:
self._balance -= amount
return None

def computeInterest(self):
"""Computes, deposits, and returns the interest."""
interest = self._balance * SavingsAccount.RATE
self.deposit(interest)
return interest

class Bank(object):
"""This class represents a bank as a dictionary of
accounts. An optional file name is also associated
with the bank, to allow transfer of accounts to and
from permanent file storage."""

def __init__(self, fileName = None):
"""Creates a new dictionary to hold the accounts.
If a file name is provided, loads the accounts from
a file of pickled accounts."""
self._accounts = {}
self.fileName = fileName
if fileName != None:
fileObj = open(fileName, 'rb')
while True:
try:
account = pickle.load(fileObj)
self.add(account)
except EOFError:
fileObj.close()
break

def add(self, account):
"""Inserts an account using its PIN as a key."""
self._accounts[account.getPin()] = account

def remove(self, pin):
return self._accounts.pop(pin)

def get(self, pin):
return self._accounts.get(pin, None)

def computeInterest(self):
"""Computes interest for each account and
returns the total."""
total = 0
for account in self._accounts.values():
total += account.computeInterest()
return total

def __str__(self):
"""Return the string rep of the entire bank."""
return '\n'.join(map(str, self._accounts.values()))

def save(self, fileName = None):
"""Saves pickled accounts to a file. The parameter
allows the user to change file names."""
if fileName != None:
self.fileName = fileName
elif self.fileName == None:
return
fileObj = open(self.fileName, 'wb')
for account in self._accounts.values():
pickle.dump(account, fileObj)
fileObj.close()
  
def testBank(number = 0):
"""Returns a bank with the specified number of accounts and/or
the accounts loaded from the specified file name."""
bank = Bank()
for i in xrange(number):
bank.add(SavingsAccount('Name' + str(i + 1),
str(1000 + i),
100.00))
return bank

Answer 1

#i have provided implementation of the required function only
def run(self):

    """Logs in users and processes their accounts."""

    failureCount = 0
    while True:
        name = input('Enter account name: ')
        pin = input('Enter pin: ')
        acc = self._bank.get(pin)
        if acc is None:
            print("Error, unrecognized PIN")
            failureCount+=1
        else:
            if acc._name!=name:
                print('Error, unrecognised name')
                failureCount+=1
            else:
                self._account=acc
                self._processAccount()
                failureCount=0
        if failureCount==3:
            print('Shutting down and calling the cops')
            break