My use of __str__() inside of another object's __str__() is not working

Question

I'm trying to use str to create a string representation of my object and use is when printing another object that uses this object. My implementation isn't working though.

I saw this: How to properly define a return string within a for loop for a Class using OOP in Python and thought I had everything correct, but I'm still not getting what I want in the output

Here is my code:

class Card:
    def __init__(self, name):
        self.name = name
    def __str__(self):
        print("using Card.__str__()")
        return self.name

class Deck:
    def __init__(self):
        self.deck = []

    def add_cards(self, cds):
        self.deck.append(cds)

    def __str__(self):
        print("using Deck.__str__()")
        temp = ""
        for i in range(len(self.deck)): # <- iterating over list of Card objs
            temp += str(self.deck[i])  # <- deck[i] is Card obj, why doesn't this use Card.__str__()?
            if i < len(self.deck)-1:
                temp += ", "
        return temp

card1 = Card("Apples")
card2 = Card("Peaches")
card3 = Card("Grapes")
card4 = Card("Pears")
cards = [card1, card2, card3, card4]
deck = Deck()
deck.add_cards(cards)
print(deck)

I'm expecting to see:

Apples, Peaches, Grapes, Pears

But instead I'm getting:

using deck.str() [<main.Card object at 0x7f7f1d1103a0>, <main.Card object at 0x7f7f1d146520>, <main.Card object at 0x7f7f1d1
46be0>, <main.Card object at 0x7f7f1d146dc0>]

What am I doing wrong???