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Python Object-Oriented Python Dice Roller RPG Roller

Posted by Cross Ender
Cross Ender
9,567 Points

My hand isn't working. It keeps saying "Cannot get the length of a 'Hand'" IDLE returns an empty list

I can't find the problem.

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):
        super().__init__(sides=20)
hands.py 
from dice import D20
class Hand(list):
    @classmethod
    def roll(self):
        d1 = D20()
        d2 = D20()
        super().append(d1.value)
        super().append(d2.value)

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

2 Answers

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

Here's a few hints:

  • a classmethod would have an extra first argument that represents the class itself
  • I don't think you can call append() except onto an instance
  • the roll method should take an argument for the number of D20's to roll
  • your roll method doesn't return anything yet
  • remember to return a new instance of the Hand object
Mickey Asavanant
Mickey Asavanant
8,237 Points
Mickey Asavanant
Mickey Asavanant
8,237 Points

I stuck on this one too. I don't think I understand the question clearly. Are we supposed to create a class method or instance method? If we are going to create a class method, is the question asking to return a list of 2 D20 objects?

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

The instructions gave an example of calling it as "Hand.roll(2)", which would indicate that it is a class method.

The instructions also say it should return an instance of the Hand object (with the D20 objects inside it).