Bummer: Can't get the length of a 'Hand'

Question

I am struggling with python classes. What exactly am I doing wrong here?

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, Die

class Hand(list):
    @property
    def total(self):
        return sum(self)

    def roll(self, num):
        for i in range(num):
            self.append(dice.D20())

    def __len__(self):
        return len(super())

Answer 1 · 2018-08-09T18:22:11Z

August 9, 2018 6:22pm

Hi Ryan, you have the right idea. Here are some items to correct in hand.py:

less important:

do not need to import die. Only D20 is needed.
for class methods it is customary to use cls instead of self as the first parameter

important:

fix mixed use of TAB and SPACE in the code. All spaces is preferred.
need to declare roll as class method using the @classmethod decorator so it's available without an instance.
a class method does not have an instance to operate upon. so create one using

    hand = cls()

D20 is directly available due to import so it can be appended directly using hand.append(D20())
finally, need to return the created instance: return hand
do not need to create local __len__ method. It is inherited automatically from list

Post back if you need more help. Good luck!!

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Ryan Gostic

Ryan Gostic

Bummer: Can't get the length of a 'Hand'

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Chris Freeman

Chris Freeman

Ryan Gostic

Ryan Gostic