# Lets suppose we want to decorate a class such that it prints a warning

# when we try to spend more than what we've got

def add_warning(cls):

prev_spend = getattr(cls, 'spend')

def new_spend(self, money):

if money > self.money:

print("You are spending more than what you have, "

"a debt has been generated in your account!!")

prev_spend(self, money)

setattr(cls, 'spend', new_spend)

return cls

@add_warning

class Buy:

def __init__(self, money):

self.money = money

self.debt = 0

def spend(self, money):

self.money -= money

if self.money < 0:

self.debt = abs(self.money) # the debt is considered positive

self.money = 0

print("Current Balance = {}".format(self.money))

b = Buy(1000)

b.spend(1200)