File "<string>", line 19, in <module> error is related to what?

[Frankduc]

Hello,

I am trying to understand what is going on:

class Portfolio:
    def __int__(self):
        self.holdings = {}  #key = ticker, Value = number of shares
        
    def buy(self, ticker, shares):
        self.holdings[ticker] = self.holdings.get(ticker, 0) + shares
        
    def sell(self, ticker, shares):
        self.holdings[ticker] = self.holdings.get(ticker, 0) - shares
        
    def __iter__(self):
        return iter(self.holdings.items())
        
        
p = Portfolio()
p.buy('Alpha', 15)
p.buy('Beta', 23)
p.buy('Gamma', 9)
p.buy('Gamma', 20)
p.sell('Beta', 5)

for (ticker, shares) in p:
    print(ticker, shares)

According to the errors output:

Error:
Traceback (most recent call last):
  File "<string>", line 19, in <module>
  File "<string>", line 9, in buy
AttributeError: 'Portfolio' object has no attribute 'holdings'
> 

I am missing a module? But which one?

Thank you