deck.py

from random import random

class Deck:
    def __init__(self, cards):
        self.cards = cards

    def get_deck(self):
        """
        Returns the deck 'updated', after shuffling it.
        """
        self.shuffle_deck()
        return self.cards

    def draw_card(self):
        """
        Returns the top card of the deck to the player's cards.

        P.S.: This function will never be called if the deck is empty.
        That will be more understandable when the class Game be implemented.
        That class will check if it has cards on the deck, and if doesn't, it
        will call the create_new_deck_with_played_cards method.
        """

        return self.cards.pop(-1)

    def shuffle_deck(self):
        """
        Takes the self.cards list and shuffle using randint function.
        """
        amount_of_cards_available = len(self.cards)
        indexes_shuffled = []
        deck_shuffled = []
        for i in range(amount_of_cards_available):
            num = random.randint(0, amount_of_cards_available)
            if num not in indexes_shuffled:
                indexes_shuffled.append(num)

        for i in range(amount_of_cards_available):
            deck_shuffled.append(self.cards[indexes_shuffled[i]])

        self.cards = deck_shuffled


    def is_empty(self):
        """
        Returns True if the deck is empty, otherwise returns False
        """
        if self.cards == []:
            return True

        return False

    def create_new_deck_with_played_cards(self, played_cards):
        """
        It takes the played cards and create a new deck, then it returns
        the self.get_deck() method that shuffles the deck and returns it
        """
        print("Creating new deck with the cards played...\n")
        self.cards = played_cards
        return self.get_deck()


import unittest

class TestDeck(unittest.TestCase):
    def test_empty_deck(self):
        deck = Deck([])
        self.assertListEqual(deck.cards, [])

    def test_deck_with_cards(self):
        deck = Deck([1,2,3,4,5])
        self.assertListEqual(deck.cards, [1,2,3,4,5])

    def test_shuffled_deck_other_than_base_deck(self):
        deck = Deck([1,2,3,4,5])
        cards_before = deck.cards.copy()
        deck.shuffle_deck()
        self.assertNotEqual(deck.cards, cards_before)

    def test_draw_card(self):
        deck = Deck([1,2,3,4,5])
        card = deck.draw_card()
        self.assertEqual(card, 5)
        self.assertEqual(len(deck.cards), 4)

    def test_draw_card_when_no_cards_available(self):
        deck = Deck([])
        card = deck.draw_card()
        self.assertEqual

if __name__ == "__main__":
    unittest.main()