1. Intro to Python - Learn by Doing!

print("Hello, World!")

print("Hello, my name is [Your Name]!")
print("I am learning Python!")
print("This is awesome!")

# This is a comment - Python ignores it (the # symbol makes a comment)
name = "Alex"
age = 14
height = 5.5  # in feet
is_student = True

print("Name:", name)
print("Age:", age)
print("Height:", height)
print("Is a student:", is_student)

score = 0
print("Starting score:", score)

score = 10
print("After getting points:", score)

score = score + 5  # Add 5 to the current score
print("After bonus points:", score)

# Addition
result = 10 + 5
print("10 + 5 =", result)

# Subtraction
result = 20 - 7
print("20 - 7 =", result)

# Multiplication
result = 6 * 7
print("6 × 7 =", result)

# Division (always gives a decimal)
result = 15 / 3
print("15 ÷ 3 =", result)

# Integer Division (gives whole number, no decimal)
result = 17 // 5
print("17 ÷ 5 (whole number) =", result)

# Modulo (remainder after division)
result = 17 % 5
print("17 mod 5 (remainder) =", result)

# Exponents (powers)
result = 2 ** 8
print("2 to the power of 8 =", result)

# Calculate the area of a rectangle
length = 10
width = 5
area = length * width
print(f"A rectangle with length {length} and width {width} has area {area}")

# Convert temperature from Fahrenheit to Celsius
fahrenheit = 68
celsius = (fahrenheit - 32) * 5/9
print(f"{fahrenheit}°F is {celsius:.1f}°C")

# Calculate how many hours in a year
hours_per_day = 24
days_per_year = 365
hours_per_year = hours_per_day * days_per_year
print(f"There are {hours_per_year} hours in a year!")

# Creating strings
greeting = "Hello"
name = "Sam"

# Combining strings (concatenation)
message = greeting + " " + name + "!"
print(message)  # Hello Sam!

# Repeating strings
laugh = "ha" * 5
print(laugh)  # hahahahaha

# Multi-line strings
poem = """Roses are red,
Violets are blue,
Python is fun,
And so are you!"""
print(poem)

text = "python is awesome"

# Make uppercase
print(text.upper())  # PYTHON IS AWESOME

# Make lowercase
print(text.lower())  # python is awesome

# Capitalize first letter
print(text.capitalize())  # Python is awesome

# Make Title Case
print(text.title())  # Python Is Awesome

# Count how many times a letter appears
print(text.count("o"))  # 2

# Replace words
print(text.replace("awesome", "amazing"))  # python is amazing

# Check if text starts with something
print(text.startswith("python"))  # True

# Get the length of a string
print(len(text))  # 17

word = "PYTHON"

# Get individual characters (starts counting at 0!)
print(word[0])  # P (first character)
print(word[1])  # Y (second character)
print(word[-1])  # N (last character)

# Get a slice of the string
print(word[0:3])  # PYT (characters 0, 1, 2)
print(word[2:5])  # THO (characters 2, 3, 4)
print(word[2:])   # THON (from position 2 to end)
print(word[:4])   # PYTH (from start to position 4)

# A list of favorite foods
foods = ["pizza", "tacos", "ice cream", "sushi"]
print(foods)

# A list of numbers
lucky_numbers = [7, 13, 21, 42]
print(lucky_numbers)

# A mixed list (different types!)
random_stuff = ["apple", 42, 3.14, True]
print(random_stuff)

# Access items by position (index)
print("First food:", foods[0])  # pizza
print("Second food:", foods[1])  # tacos
print("Last food:", foods[-1])  # sushi

# Start with a list
colors = ["red", "blue", "green"]
print("Original:", colors)

# Add an item to the end
colors.append("yellow")
print("After append:", colors)

# Insert an item at a specific position
colors.insert(1, "orange")  # Insert at position 1
print("After insert:", colors)

# Remove an item
colors.remove("blue")
print("After remove:", colors)

# Get the last item and remove it
last_color = colors.pop()
print("Popped:", last_color)
print("Remaining:", colors)

# Change an item
colors[0] = "purple"
print("After change:", colors)

# How many items?
print("Number of colors:", len(colors))

# Sort a list
numbers = [5, 2, 8, 1, 9]
numbers.sort()
print("Sorted numbers:", numbers)

# Reverse a list
numbers.reverse()
print("Reversed:", numbers)

# Check if something is in a list
fruits = ["apple", "banana", "cherry"]
if "banana" in fruits:
    print("Yes, banana is in the list!")

# Combine lists
list1 = [1, 2, 3]
list2 = [4, 5, 6]
combined = list1 + list2
print("Combined:", combined)

age = 16

if age >= 18:
    print("You can vote!")
else:
    print("You're not old enough to vote yet.")

score = 85

if score >= 90:
    print("Grade: A - Excellent!")
elif score >= 80:
    print("Grade: B - Great job!")
elif score >= 70:
    print("Grade: C - Good work!")
elif score >= 60:
    print("Grade: D - You passed!")
else:
    print("Grade: F - Study more next time!")

x = 10
y = 20

# Equal to
print(x == y)  # False

# Not equal to
print(x != y)  # True

# Greater than
print(x > y)   # False

# Less than
print(x < y)   # True

# Greater than or equal to
print(x >= 10)  # True

# Less than or equal to
print(y <= 30)  # True

age = 17
has_permission = True

# Using "and" (both must be True)
if age >= 16 and has_permission:
    print("You can drive!")

# Using "or" (at least one must be True)
is_weekend = True
is_holiday = False

if is_weekend or is_holiday:
    print("No school today!")

# Using "not" (reverses True/False)
is_raining = False
if not is_raining:
    print("Let's go outside!")

password = "python123"
user_input = "python123"

if len(user_input) < 8:
    print("Password too short!")
elif user_input == password:
    print("Access granted! Welcome!")
else:
    print("Incorrect password. Try again.")

# Count from 0 to 4
for i in range(5):
    print("Count:", i)

# Count from 1 to 10
for i in range(1, 11):
    print(i)

# Count by 2s
for i in range(0, 11, 2):
    print(i)  # 0, 2, 4, 6, 8, 10

# Loop through a list of fruits
fruits = ["apple", "banana", "cherry", "date"]

for fruit in fruits:
    print("I like", fruit)

# With index numbers
for i in range(len(fruits)):
    print(f"{i+1}. {fruits[i]}")

# Countdown
count = 5
while count > 0:
    print(count)
    count = count - 1  # or count -= 1
print("Blast off! 🚀")

# Keep asking until we get the right answer
secret_number = 7
guess = 0

while guess != secret_number:
    guess = int(input("Guess the number (1-10): "))
    if guess < secret_number:
        print("Too low!")
    elif guess > secret_number:
        print("Too high!")
    else:
        print("Correct! You win!")

# Break - stops the loop immediately
for i in range(10):
    if i == 5:
        break  # Stop when we reach 5
    print(i)  # Prints 0, 1, 2, 3, 4

# Continue - skips to the next iteration
for i in range(5):
    if i == 2:
        continue  # Skip 2
    print(i)  # Prints 0, 1, 3, 4

# Print a multiplication table
for i in range(1, 4):
    for j in range(1, 4):
        result = i * j
        print(f"{i} × {j} = {result}")
    print()  # Blank line after each row

# Define a function
def greet():
    print("Hello, there!")
    print("Welcome to Python!")

# Call (use) the function
greet()
greet()  # You can call it multiple times!

# Function that takes input
def greet_person(name):
    print(f"Hello, {name}!")
    print("Nice to meet you!")

# Call with different names
greet_person("Alice")
greet_person("Bob")
greet_person("Charlie")

def introduce(name, age, hobby):
    print(f"Hi! My name is {name}.")
    print(f"I am {age} years old.")
    print(f"I love {hobby}!")

introduce("Sam", 15, "playing guitar")
introduce("Jamie", 14, "reading books")

# Function that calculates and returns a value
def add_numbers(a, b):
    result = a + b
    return result

# Use the returned value
sum1 = add_numbers(5, 3)
print("5 + 3 =", sum1)

sum2 = add_numbers(10, 20)
print("10 + 20 =", sum2)

# Calculate the area of a circle
def circle_area(radius):
    pi = 3.14159
    area = pi * radius ** 2
    return area

print("Circle area:", circle_area(5))

# Check if a number is even
def is_even(number):
    if number % 2 == 0:
        return True
    else:
        return False

print(is_even(10))  # True
print(is_even(7))   # False

# Convert temperature
def fahrenheit_to_celsius(f):
    c = (f - 32) * 5/9
    return round(c, 1)  # Round to 1 decimal place

print(f"68°F = {fahrenheit_to_celsius(68)}°C")

# If no age is provided, it uses 0 as default
def greet_with_age(name, age=0):
    if age == 0:
        print(f"Hello, {name}!")
    else:
        print(f"Hello, {name}! You are {age} years old.")

greet_with_age("Alice", 15)  # Uses the provided age
greet_with_age("Bob")        # Uses default age (0)

# A dictionary of a person's info
person = {
    "name": "Alex",
    "age": 16,
    "city": "New York",
    "hobby": "gaming"
}

# Access values using keys
print("Name:", person["name"])
print("Age:", person["age"])

# Start with a student's grades
grades = {
    "math": 85,
    "science": 92,
    "english": 88
}

print("Original grades:", grades)

# Add a new subject
grades["history"] = 90
print("After adding history:", grades)

# Update an existing grade
grades["math"] = 95
print("After updating math:", grades)

# Remove a subject
del grades["science"]
print("After removing science:", grades)

# Get all keys
print("Subjects:", list(grades.keys()))

# Get all values
print("Scores:", list(grades.values()))

# Loop through keys and values
favorite_foods = {
    "Alice": "pizza",
    "Bob": "tacos",
    "Charlie": "sushi"
}

for person in favorite_foods:
    food = favorite_foods[person]
    print(f"{person}'s favorite food is {food}")

# Or use .items() for cleaner code
for person, food in favorite_foods.items():
    print(f"{person} loves {food}!")

# A dictionary of students, each with their own dictionary
students = {
    "student1": {
        "name": "Emma",
        "age": 15,
        "grade": "A"
    },
    "student2": {
        "name": "Noah",
        "age": 16,
        "grade": "B"
    }
}

print(students["student1"]["name"])  # Emma
print(students["student2"]["grade"])  # B

def calculator():
    print("=== Simple Calculator ===")
    num1 = float(input("Enter first number: "))
    num2 = float(input("Enter second number: "))
    operation = input("Choose operation (+, -, *, /): ")
    
    if operation == "+":
        result = num1 + num2
    elif operation == "-":
        result = num1 - num2
    elif operation == "*":
        result = num1 * num2
    elif operation == "/":
        if num2 != 0:
            result = num1 / num2
        else:
            print("Error: Cannot divide by zero!")
            return
    else:
        print("Invalid operation!")
        return
    
    print(f"Result: {num1} {operation} {num2} = {result}")

# To use it: calculator()

import random

def guessing_game():
    print("=== Number Guessing Game ===")
    secret = random.randint(1, 20)
    attempts = 0
    max_attempts = 5
    
    print("I'm thinking of a number between 1 and 20!")
    
    while attempts < max_attempts:
        guess = int(input(f"Attempt {attempts + 1}/{max_attempts} - Your guess: "))
        attempts += 1
        
        if guess == secret:
            print(f"🎉 Correct! You won in {attempts} attempts!")
            return
        elif guess < secret:
            print("Too low! Try higher.")
        else:
            print("Too high! Try lower.")
    
    print(f"Game over! The number was {secret}")

# To play: guessing_game()

def todo_list():
    tasks = []
    
    while True:
        print("\n=== To-Do List ===")
        print("1. View tasks")
        print("2. Add task")
        print("3. Remove task")
        print("4. Quit")
        
        choice = input("Choose an option (1-4): ")
        
        if choice == "1":
            if len(tasks) == 0:
                print("No tasks yet!")
            else:
                print("\nYour tasks:")
                for i, task in enumerate(tasks, 1):
                    print(f"{i}. {task}")
        
        elif choice == "2":
            task = input("Enter new task: ")
            tasks.append(task)
            print(f"Added: {task}")
        
        elif choice == "3":
            if len(tasks) == 0:
                print("No tasks to remove!")
            else:
                for i, task in enumerate(tasks, 1):
                    print(f"{i}. {task}")
                index = int(input("Enter task number to remove: ")) - 1
                if 0 <= index < len(tasks):
                    removed = tasks.pop(index)
                    print(f"Removed: {removed}")
                else:
                    print("Invalid task number!")
        
        elif choice == "4":
            print("Goodbye!")
            break
        
        else:
            print("Invalid choice!")

# To run: todo_list()

def word_counter(text):
    # Count words
    words = text.split()
    word_count = len(words)
    
    # Count characters (without spaces)
    char_count = len(text.replace(" ", ""))
    
    # Count vowels
    vowels = "aeiouAEIOU"
    vowel_count = sum(1 for char in text if char in vowels)
    
    # Results
    print(f"Text: {text}")
    print(f"Words: {word_count}")
    print(f"Characters: {char_count}")
    print(f"Vowels: {vowel_count}")

# Try it:
word_counter("Python is an amazing programming language!")