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Python Object-Oriented Python Dice Roller RPG Roller

Hand.roll Exercise

Can anyone explain what I'm missing in the hands.py script? I haven't been given any hints. My thought is that it has something to do with how the results are being returned.

dice.py
import random


class Die:
    def __init__(self, sides=2):
        if sides < 2:
            raise ValueError("Can't have fewer than two sides")
        self.sides = sides
        self.value = random.randint(1, sides)

    def __int__(self):
        return self.value

    def __add__(self, other):
        return int(self) + other

    def __radd__(self, other):
        return self + other

class D20(Die):
    def __init__(self, sides = 20):
        super().__init__(sides = sides)
hands.py
from dice import Die
from dice import D20

class Hand(list):
    def __init__(self):
        super().__init__()

    def __repr__(self):
        return str(self.value)

    @property
    def total(self):
        return sum(self)

    @classmethod
    def roll(cls, number):
        die = []

        for _ in range(number):
            die.append(D20())

        return die

1 Answer

Steven Parker
Steven Parker
229,786 Points

It looks like you've implemented some stuff not asked for in the instructions. You may need to remove the "extras".

But the "roll" method should return an instance of "Hand" instead of an ordinary list.

Why would we be using a classmethod to return an instance though? Wouldn't a classmethod be used to return something related to the class itself?

Steven Parker
Steven Parker
229,786 Points

That's another possible use of a class method. But since you need to have an instance to start with to use an instance method, a class method is a logic choice if you need something to create a new instance as part of what it does.

So a classmethod in a case like this is essentially creating all of the class variables to create the opportunity to make an instance?

Steven Parker
Steven Parker
229,786 Points

This particular method is intended to create a new instance and add content to it, but neither one is a requirement of a generic class method.