append arguments in a list of a class using another class?

Question

This code generate 52 deck of cards. Here in this code I didn't understand why he/she appends arguments a and b in self.deck list using Card class in class Deck __init__ method???

suits = ('Hearts', 'Diamonds', 'Spades', 'Clubs')
ranks = ('Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine', 'Ten', 'Jack', 'Queen', 'King', 'Ace')

class Card():

    def __init__(self, suit, rank):
        self.suit = suit
        self.rank = rank

    def __repr__(self):
        return self.rank + " of " + self.suit


class Deck():

    def __init__(self):
        self.deck = []
        for a in suits:
            for b in ranks:
                self.deck.append(Card(a, b))

    def __repr__(self):
        deck_comp = ''
        for card in self.deck:
            deck_comp += "\n "+card.__repr__()
        return "The deck has: " + deck_comp

deck = Deck()
print(deck) 

Answer 1

The name of the variables doesn't help you. The code iterate over the suits and the ranks to get all combination of them, the Card is to create a new instance with the 2 param : suit and rank

Hearts Two
Hearts Three
Hearts Four
...
Diamonds Two
Diamonds Three
Diamonds Four
...

Use meaningfull names, and you can't use a print to understand better :

def __init__(self):
    self.deck = []
    for suit in suits:
        print(suit) # for understanding only
        for rank in ranks:
            print(suit, rank) # for understanding only
            self.deck.append(Card(suit, rank))

This correspond to a itertools.product between the 2 lists, you can map to a Card instance and keep the list

def __init__(self):
    self.deck = list(map(lambda x: Card(*x), product(suits, ranks)))