TDM 10200: Project 12 — Spring 2023

Motivation: Learning classes in Python

Scope: Object Oriented Python

Make sure to read about, and use the template found here, and the important information about projects submissions here.

Objects and Classes in Python

A class can be considered a outline made by the user for creating objects. An easy way to think of it is class is a blueprint or sketch of a of a car, it contains all of the details we need to know, windows, doors, engine etc. Based on all the details and descriptions we build the vehicle. The car itself is the object. Since we can have many cars created using the same description and details the idea is that we can create many objects from a class. An object is an instance of the class with actual values. An object is an (actual) specific car. A red compact car with black interior and tinted windows. You can now create multiple instances, using the blueprint of a class as a guide, to help you know what information is required.

Objects consist of:

State: attributes/properties of an object
Behavior: the methods of the object and also its response to other objects
Identity: gives a unique name to the object and that allows for interaction between objects.

Vehicle Example
Identity	State/Attributes	Behavior
Miata	Mazda, Red, 2019	acceleration, steering, braking

Instantiating a Class == Declaring Objects All instances share the same attributes and the same behavior but the values of the attributes(State) are unique.

Insider Knowledge

ONE

Let’s start simple and declare an object

class CAR:
    #attibute
    attr1 = "red"
    attr2 = "fast"

    #sample method
    #self refers to the class of which the method belongs
    def fun(self):
        print("The car is", self.attr1)
        print("The car is", self.attr2)
#object instantiaton
Miata = CAR()

What happens when you type: print(Miata)
What happens when you type: Miata.fun()
Now create and declare your own object. We encourage you to make a class of your own and try it out, e.g., make a class for a BOOK or a KITCHEN or a UNIVERSITY or a DOG.

You might want to also experiment further with the Miata, e.g., you might want to try: Miata.attr1 and Miata.attr2 and add some attributes. It is worthwhile to play a little bit with the CAR!

Items to submit

Answers to the questions a,b,c above.
Code used to solve this problem.
Output from running the code.

TWO

Lets play with cards!
The code below defines two different types of classes:

class Card:
#mapping each possible card number(2-10,J,Q,K,A) to a numerical value
    _value_dict = {"2": 2, "3": 3, "4": 4, "5": 5, "6": 6, "7": 7, "8":8, "9":9, "10": 10, "j": 11, "q": 12, "k": 13, "a": 14}
    def __init__(self, number, suit):
        if str(number).lower() not in [str(num) for num in range(2, 11)] + list("jqka"):
            raise Exception("Number wasn't 2-10 or J, Q, K, or A.")
        else:
            self.number = str(number).lower()
        if suit.lower() not in ["clubs", "hearts", "diamonds", "spades"]:
            raise Exception("Suit wasn't one of: clubs, hearts, spades, or diamonds.")
        else:
            self.suit = suit.lower()

    def __str__(self):
        return(f'{self.number} of {self.suit.lower()}')

    def __repr__(self):
        return(f'Card(str({self.number}), "{self.suit}")')

    def __eq__(self, other):
        if self.number == other.number:
            return True
        else:
            return False

    def __lt__(self, other):
        if self._value_dict[self.number] < self._value_dict[other.number]:
            return True
        else:
            return False

    def __gt__(self, other):
        if self._value_dict[self.number] > self._value_dict[other.number]:
            return True
        else:
            return False

    def __hash__(self):
        return hash(self.number)

class Deck:
    brand = "Bicycle"
    _suits = ["clubs", "hearts", "diamonds", "spades"]
    _numbers = [str(num) for num in range(2, 11)] + list("jqka")

    def __init__(self):
        self.cards = [Card(number, suit) for suit in self._suits for number in self._numbers]

    def __len__(self):
        return len(self.cards)

    def __getitem__(self, key):
        return self.cards[key]

    def __setitem__(self, key, value):
        self.cards[key] = value

Create an instance of the class Card and call it my_card. Then run: print(my_card) and also run: my_card
What is the difference in the output?
Create an instance of the class Deck and call it my_deck. Now what is the number of items you will find in the object my_deck

Helpful Hint (for c)

len(my_deck)

It is important to point out that a Python function inside a class is called a method. We can initialize values using constructors there is an

__int__()

function that is called whenever a new object of that class is instantiated.

THREE

Modify the Class Deck to return a string that says "a bicycle deck with 52 cards".

Items to submit

Code used to solve this problem.
Output from running the code.

FOUR

Let’s create a new class called Player We will use this to represent a player in a game. The following features must be included:

A deck to draw from
A hand of cards
The name of the player
A draw method that draws a card from the deck and adds it to the hand.

Helpful Hint

Knowing that each person will have a different name, the name attribute will be an instance attribute. The name argument will be used to assign a name to a player, and the deck argument is used to assign the deck to the player. The hand of cards should be an empty list at initialization. The draw method will be used to draw a card from the deck and add it to a player’s hand.

Items to submit

Answers to the question above
Code used to solve this problem
Output from running the code.

FIVE

What card does Liz draw? Create a Deck and a Player, and draw a card from the deck. Print the value on the card that is drawn.

Helpful Hint

my_deck1 = Deck()
player1 = Player("Liz", my_deck1)
card = player1.draw()
print(card)

Items to submit

The answer to the question above.
Code used to solve this problem.
Output from running the code.

Please make sure to double check that your submission is complete, and contains all of your code and output before submitting. If you are on a spotty internet connection, it is recommended to download your submission after submitting it to make sure what you think you submitted, was what you actually submitted.

In addition, please review our submission guidelines before submitting your project.