🏗️ Object-Oriented Programming

# Creating a simple class from Session 8
class Dog:
    """A simple Dog class"""
    pass  # Empty class for now

# Create objects (instances) of the class
dog1 = Dog()
dog2 = Dog()

print("dog1:", dog1)
print("dog2:", dog2)
print("Same object?", dog1 == dog2)  # False - different objects!
print("Type:", type(dog1))

# __init__ method from Session 8
class Dog:
    """A Dog class with attributes"""
    
    def __init__(self, name, age, breed):
        """Initialize a new Dog object"""
        self.name = name      # Instance attribute
        self.age = age        # Instance attribute
        self.breed = breed    # Instance attribute
        print(f"A new dog '{name}' has been created! 🐕")

# Create dog objects
buddy = Dog("Buddy", 3, "Golden Retriever")
max = Dog("Max", 5, "German Shepherd")

# Access attributes
print(f"\\n{buddy.name} is a {buddy.age}-year-old {buddy.breed}")
print(f"{max.name} is a {max.age}-year-old {max.breed}")

# Understanding self from Session 8
class Person:
    def __init__(self, name):
        print(f"self is: {self}")
        self.name = name
    
    def introduce(self):
        print(f"Hi, I'm {self.name}!")
        print(f"self inside method: {self}")

# Create objects
alice = Person("Alice")
print(f"alice variable: {alice}")
print()
alice.introduce()

print("\\n--- Another person ---")
bob = Person("Bob")
bob.introduce()

# Instance methods from Session 8
class Dog:
    def __init__(self, name, age):
        self.name = name
        self.age = age
        self.energy = 100
    
    def bark(self):
        """Make the dog bark"""
        print(f"{self.name} says: Woof! Woof! 🐕")
    
    def sleep(self):
        """Make the dog sleep"""
        self.energy = 100
        print(f"{self.name} is sleeping... 💤")
        print(f"Energy restored to {self.energy}!")
    
    def play(self, minutes):
        """Play and use energy"""
        energy_used = minutes * 2
        if energy_used <= self.energy:
            self.energy -= energy_used
            print(f"{self.name} played for {minutes} minutes! 🎾")
            print(f"Energy left: {self.energy}")
        else:
            print(f"{self.name} is too tired to play! 😴")
    
    def birthday(self):
        """Increase dog's age by 1"""
        self.age += 1
        print(f"🎂 Happy Birthday {self.name}! Now {self.age} years old!")

# Create a dog and use methods
buddy = Dog("Buddy", 3)
buddy.bark()
buddy.play(30)
buddy.play(20)
buddy.sleep()
buddy.birthday()

# __repr__ method from Session 8
class Dog:
    def __init__(self, name, age, breed):
        self.name = name
        self.age = age
        self.breed = breed
    
    def __repr__(self):
        """Return a nice string representation"""
        return f"Dog(name='{self.name}', age={self.age}, breed='{self.breed}')"

# Without __repr__: <Dog object at 0x...>
# With __repr__: Dog(name='Buddy', age=3, breed='Golden Retriever')

buddy = Dog("Buddy", 3, "Golden Retriever")
print(buddy)

# Also works in lists!
dogs = [
    Dog("Max", 5, "German Shepherd"),
    Dog("Luna", 2, "Labrador")
]
print("\\nList of dogs:", dogs)

# Bank Account class from Session 8
class BankAccount:
    """A simple bank account"""
    
    def __init__(self, owner, balance=0):
        self.owner = owner
        self.balance = balance
        print(f"Account created for {owner} with ${balance:.2f}")
    
    def deposit(self, amount):
        """Add money to account"""
        if amount > 0:
            self.balance += amount
            print(f"✅ Deposited ${amount:.2f}. New balance: ${self.balance:.2f}")
        else:
            print("❌ Deposit amount must be positive!")
    
    def withdraw(self, amount):
        """Remove money from account"""
        if amount > self.balance:
            print(f"❌ Insufficient funds! Balance: ${self.balance:.2f}")
        elif amount <= 0:
            print("❌ Withdrawal amount must be positive!")
        else:
            self.balance -= amount
            print(f"✅ Withdrew ${amount:.2f}. New balance: ${self.balance:.2f}")
    
    def get_balance(self):
        """Return current balance"""
        return self.balance
    
    def __repr__(self):
        return f"BankAccount(owner='{self.owner}', balance=${self.balance:.2f})"

# Test the bank account
account = BankAccount("Alice", 1000)
print()
account.deposit(500)
account.withdraw(200)
account.withdraw(2000)  # Insufficient funds
print(f"\\nCurrent balance: ${account.get_balance():.2f}")
print(account)

# Circle class from Session 8
import math

class Circle:
    """A class to represent a circle"""
    
    def __init__(self, radius):
        self.radius = radius
    
    def area(self):
        """Calculate the area of the circle"""
        return math.pi * self.radius ** 2
    
    def circumference(self):
        """Calculate the circumference"""
        return 2 * math.pi * self.radius
    
    def diameter(self):
        """Return the diameter"""
        return self.radius * 2
    
    def __repr__(self):
        return f"Circle(radius={self.radius})"

# Create circles and calculate
circle1 = Circle(5)
circle2 = Circle(10)

print(f"Circle 1: {circle1}")
print(f"  Area: {circle1.area():.2f}")
print(f"  Circumference: {circle1.circumference():.2f}")
print(f"  Diameter: {circle1.diameter()}")

print(f"\\nCircle 2: {circle2}")
print(f"  Area: {circle2.area():.2f}")