How to edit a instance variable?

I’m new to python and as I was doing an assignment for class, I got stuck using init method.

class Customer(object):
    def __init__(self, number, name):

        self.name = name
        self.number = number
        self.orders = []
        
        
    def addorder(self, order):
        self.orders.extend(order) 
        return self.orders

    def __str__(self):
        return str(self.orders)


Customer('308','John').addorder((1,2,3,4))

print(Customer('308','John'))

The output is an empty list [].

I want the output to be [1,2,3,4]

What am I doing wrong here?

>Solution :

Keep in mind that each time you "call" a class, you instantiate a new object (this is why in many languages other than Python, this actually requires the keyword new). So, in your example, you’re instantiating two different objects (that don’t share their properties). Instead, you should save them in a variable:

customer = Customer("308", "John")
customer.addorder((1, 2, 3, 4))
print(customer)