Newbie Class Inheritance Question (python)

Question

class Deck(Cards):
    def __init__(self):
        
        self.mycardset = []
        for num in self.values:
            for shp in self.suites:
                self.mycardset.append(num+' of '+ shp)
         
        
            
  
    def shuffleDeck(self):
      
        self.mycardset = shuffle(self.mycardset)  


def main():
    deck = Deck()
  
    print(f'[Current Deck]\n{deck.mycardset}')
    shuffled_deck = deck.shuffleDeck()
    print(f'[Shuffled Deck]\n{shuffled_deck.mycardset}')

AttributeError: 'NoneType' object has no attribute 'mycardset'

I don't think it's saved on the list, how can I fix it?

Answer 1

suffleDeck method doesn't return anything (or returns a None), modifying your class in place, so you are assigning shuffled_deck as None, hence your error. Just call your method on the deck variable and access the mycardset attribute from it instead

def main():
    deck = Deck()
  
    print(f'[Current Deck]\n{deck.mycardset}')
    # Suffle deck in place
    deck.shuffleDeck()
    print(f'[Shuffled Deck]\n{deck.mycardset}')

Other option would be to modify shuffleDeck() to return self

def shuffleDeck(self):
    self.mycardset = shuffle(self.mycardset)
    return self

but keep in mind, this still modifies deck as well, since now both variables point to the same object in memory. If you want to create a new deck and shuffle, while maintaining the original object, simplest way would be to copy the original deck before shuffling

import copy

def shuffleDeck(self):
    new = copy.deepcopy(self)
    new.mycardset = shuffle(self.mycardset)
    return new