Mutable object

class Account:
  def __init__(self,an,bl):
    self.accno=an
    self.balance=bl
  def deposit(self,amt):
    self.balance=self.balance+amt
  def withdraw(self,amt):
    self.balance=self.balance-amt
  def showBalance(self):
    print("AccNo :",self.accno)
    print("Balance :",self.balance)

a=Account(4117,5000)
a.showBalance()
a.deposit(3000)
a.showBalance()
a.withdraw(2000)
a.showBalance()

class worker:
  def __init__(self,n,w,d):
    self.name=n
    self.wages=w
    self.wdays=d
  def showData(self):
    print("Name is ",self.name)
    print("Wages is ",self.wages)
    print("Wdays is ",self.wdays)
  def payment(self):
    p=self.wages*self.wdays
    print("Payment is ", p)
  def addwdays(self,n):
    self.wdays=self.wdays+n

a=worker("Raja",500,5)
a.showData()
a.payment()
a.addwdays(2)
a.payment()