Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Object-Oriented Python Dice Roller Giving a Hand

Posted by jdee
jdee
6,655 Points

Why doesn't my D6 have 'value' attribute?

#################################################################

# copy_1.py

import random

class Die:
    def __init__(self, sides=2, value=0):
        if not sides >= 2:
            raise ValueError("Must have at least 2 sides")
        if not isinstance(sides, int):
            raise ValueError("Sides must be a whole number")

        self.value = value or random.randint(1, sides)

    def __int__(self):
        return self.value

    def __eq__(self, other):
        return int(self) == other

    def __ne_(self, other):
        return int(self) != other

    def __gt__(self, other):
        return int(self) > other

    def __lt__(self, other):
        return int(self) < other

    def __ge__(self, other):
        return int(self) >= other

    def __le__(self, other):
        return int(self) <= other

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

    def __radd__(self, other):
        # return self + other OR    
        return int(self) + other 

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

class D6(Die):
    def __init__(self, value=0):
        super().__init__(sides=6, value=value)

#################################################################

# script.py

from copy_1 import D6
class Hand(list):

    def __init__(self, size=8, die_class=None, *args, **kwargs):

        if not die_class:
            raise ValueError("Please provide a die_class")
        super().__init__()

        for _ in range(size):
            self.append(die_class)

hand = Hand(size=5, die_class=D6)
print(hand)                  # works
print(hand[0].value)   # AttributeError: type object 'D6' has no attribute 'value'

4 Answers

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,971 Points

The error shown is at line 42 in dice.py

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

You can verify with Ken's code at 5:00 in the video that it should be:

def __repr__(self):
    return str(self.value)
Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

In "Hand", this code appends the "die_class" itself, but you probably intended to use instances of the die class:

        for _ in range(size):
            self.append(die_class())  # use () to create an instance
jdee
jdee
6,655 Points
jdee
jdee
6,655 Points

So I added that correction, but now it does this...

print(hand)                # AttributeError: D6 has no attribute 'string'
print(hand[0].value) # Not reached
Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

Sure, because to be able to print an object directly it must define a "__str__" method, and this one doesn't have one (yet).
But printing "hand[0].value" should work now.

jdee
jdee
6,655 Points
jdee
jdee
6,655 Points

I get that, but I'm just trying to reproduce what Ken did in the video (about the 2:30 mark). What am I missing that Ken has (besides expertise? lol)

treehouse:~/workspace$ python3                                                                     
Python 3.6.4 (default, Oct 17 2019, 23:24:40)                                                      
[GCC 5.4.0 20160609] on linux                                                                      
Type "help", "copyright", "credits" or "license" for more information.                             
>>> import dice, hands                                                                             
>>> hand = hands.Hand(size=5, die_class=dice.D6)                                                   
>>> hand                                                                                           
Traceback (most recent call last):                                                                 
  File "<stdin>", line 1, in <module>                                                              
  File "/home/treehouse/workspace/dice.py", line 42, in __repr__                                   
    return str(self.string)                                                                        
AttributeError: 'D6' object has no attribute 'string'