How to create multiple objects using a class, where the objects' attributes are inserted by the-CodePudding

I think I have the basic idea down but I can't really make it work properly. I want to create 5 different objects with their own attributes, 3 each but they have to be inputs. They have to be created using another function which then returns them to show the user and also puts them in a list. This is what I have but and I can't figure out how to make it work:


class SmartPhone:
    def __init__(self, manufacturer, model, cost):
        self.manufacturer = manufacturer
        self.model = model
        self.cost = cost


manufacturer = input("Εισήγαγε τον κατασευαστή: ")
model = input("Εισήγαγε το μοντέλο: ")
cost = input("Εισήγαγε την λιανική τιμή: ")


def smart_phones(manufacturer, model, cost):
    smartPhones = []
    phone = SmartPhone(manufacturer, model, cost)
    smartPhones.append(phone)
    return "Smartphone: "   str(phone), smartPhones


smart_phones = smart_phones(manufacturer, model, cost)
for i in range(0, 5):
    print(smart_phones)

The problem lies in the smart_phones function, basically.

CodePudding user response：

You are appending an object of class SmartPhone in your list. That's why print() is returning you the address of the object in the memory. Maybe you want to append a list of manufacturer,model,cost . Something like this:

def smart_phones(manufacturer, model, cost):
   smartPhones = []
   phone = SmartPhone(manufacturer, model, cost)
   smartPhones.append([phone.manufacturer,phone.model,phone.cost])
   return "Smartphone: "    str(smartPhones)

Also, you are getting your inputs only once. To create 5 objects do this:

for i in range(0, 5):
   manufacturer = input("Creator:")
   model = input("Models:")
   cost = input("Cost:")
   print(smart_phones(manufacturer, model, cost))

CodePudding user response：

Not sure I fully understood your description but I'll try to help.

If you're trying to get 5 different SmartPhone objects, you will need to ask the user for 15 inputs (3 for each different phone). In your code you seem to ask the 3 fields for only once. You're essentialy printing the same object (with the same 3 fields) for 5 times.

Try something like this:

class SmartPhone:
    def __init__(self, manufacturer, model, cost):
        self.manufacturer = manufacturer
        self.model = model
        self.cost = cost

smartPhones = []

def smart_phones(manufacturer, model, cost):
    phone = SmartPhone(manufacturer, model, cost)
    smartPhones.append(phone)
    return "Smartphone: "   str(phone), smartPhones

for i in range(0, 5):
    smart_phones(input("Εισήγαγε τον κατασευαστή: "),input("Εισήγαγε το μοντέλο: "),input("Εισήγαγε την λιανική τιμή: "))
    
for i in range(1, 6):
    print("Phone "   str(i))
    print("Manufacturer: "   smartPhones[i].manufacturer   " ")
    print("model: "   smartPhones[i].model   " ")
    print("cost: "   smartPhones[i].cost   "\n")

Basicly this way you enter each 3 values needed for each phone. And instead of printing the place of the objects in the memory, you print each of the values within each loop.

CodePudding user response：

If you want to create a SmartPhone object, a class method is a good place to encapsulate the necessary I/O.

class SmartPhone:
    def __init__(self, manufacturer, model, cost):
        self.manufacturer = manufacturer
        self.model = model
        self.cost = cost

    @classmethod
    def from_user(cls):
        manufacturer = input("Εισήγαγε τον κατασευαστή: ")
        model = input("Εισήγαγε το μοντέλο: ")
        cost = input("Εισήγαγε την λιανική τιμή: ")
        return cls(manufacturer, model, cost)


smart_phones = [SmartPhone.from_user() for _ in range(5)]

CodePudding user response：

To print an object in an understandable way, you need to define either __repr__ or __str__ methods.

A simple example:

class SmartPhone:
    def __init__(self, manufacturer, model, cost):
        self.manufacturer = manufacturer
        self.model = model
        self.cost = cost
        
    def __repr__(self):
        return f"A ${self.cost} {self.__class__.__name__}: {self.manufacturer} {self.model}"

Define a couple of examples:

x=SmartPhone('Apple', '13', 1200)    
y=SmartPhone('Samsung', 'Galaxy', 900)

Then make a list of those:

li=[x,y]

Then you can print at will:

>>> print(li)
[A $1200 SmartPhone: Apple 13, A $900 SmartPhone: Samsung Galaxy]

>>> x
A $1200 SmartPhone: Apple 13