⚙️ Functions Part I

# Basic function from Session 6
def greet():
    """A simple greeting function"""
    print("Hello, World!")

# Call the function
greet()
greet()  # Can call it multiple times!

# Function with parameters from Session 6
def greet(name):
    """Greet a person by name"""
    print(f"Hello, {name}! Nice to meet you.")

# Call with different arguments
greet("Alice")
greet("Bob")
greet("Charlie")

# Can pass variables too
my_name = "David"
greet(my_name)

# Multiple parameters from Session 6
def add_numbers(a, b):
    """Add two numbers and print the result"""
    result = a + b
    print(f"{a} + {b} = {result}")

add_numbers(5, 3)
add_numbers(10, 20)
add_numbers(-5, 5)

# More parameters
def introduce(name, age, city):
    """Introduce a person"""
    print(f"My name is {name}, I'm {age} years old, from {city}.")

introduce("Alice", 25, "New York")
introduce("Bob", 30, "London")

# Return values from Session 6
def add(a, b):
    """Add two numbers and return the result"""
    return a + b

def multiply(a, b):
    """Multiply two numbers"""
    return a * b

# Store the returned values
sum_result = add(5, 3)
product = multiply(4, 6)

print("Sum:", sum_result)
print("Product:", product)

# Use returned values directly
print("Direct use:", add(10, 20))

# Chain function calls
total = add(multiply(2, 3), multiply(4, 5))
print("Chained:", total)  # (2*3) + (4*5) = 6 + 20 = 26

# Return multiple values from Session 6
def get_stats(numbers):
    """Calculate and return multiple statistics"""
    minimum = min(numbers)
    maximum = max(numbers)
    total = sum(numbers)
    average = total / len(numbers)
    return minimum, maximum, total, average  # Returns a tuple

# Call and unpack the results
data = [4, 8, 15, 16, 23, 42]
min_val, max_val, sum_val, avg_val = get_stats(data)

print(f"Min: {min_val}")
print(f"Max: {max_val}")
print(f"Sum: {sum_val}")
print(f"Average: {avg_val:.2f}")

# Or get as tuple
stats = get_stats(data)
print("\\nAs tuple:", stats)

# Default parameters from Session 6
def greet(name, greeting="Hello"):
    """Greet with optional custom greeting"""
    print(f"{greeting}, {name}!")

# Using default greeting
greet("Alice")

# Providing custom greeting
greet("Bob", "Hi")
greet("Charlie", "Good morning")

# More examples
def power(base, exponent=2):
    """Calculate base raised to exponent (default: square)"""
    return base ** exponent

print("\\nPower examples:")
print("5 squared:", power(5))        # Uses default exponent=2
print("2 cubed:", power(2, 3))       # Custom exponent
print("10 to 4:", power(10, 4))     # Custom exponent

# Keyword arguments from Session 6
def create_profile(name, age, city, occupation):
    """Create a user profile"""
    print(f"Name: {name}")
    print(f"Age: {age}")
    print(f"City: {city}")
    print(f"Occupation: {occupation}")
    print("---")

# Positional arguments (order matters!)
create_profile("Alice", 25, "NYC", "Engineer")

# Keyword arguments (order doesn't matter!)
create_profile(
    occupation="Designer",
    name="Bob",
    city="LA",
    age=30
)

# Mix of positional and keyword
create_profile("Charlie", 35, city="Chicago", occupation="Manager")

# Variable scope from Session 6
global_var = "I'm global!"  # Global variable

def my_function():
    local_var = "I'm local!"  # Local variable
    print("Inside function:")
    print("  Global:", global_var)  # Can access global
    print("  Local:", local_var)    # Can access local

my_function()

print("\\nOutside function:")
print("  Global:", global_var)  # Can access global
# print("  Local:", local_var)  # ERROR! local_var doesn't exist here

# Variables with same name in different scopes
x = 10  # Global x

def test_scope():
    x = 20  # Local x (shadows global x)
    print("Inside function, x =", x)

test_scope()
print("Outside function, x =", x)  # Global x unchanged

# Common built-in functions from Session 6

# Type functions
print("type(42):", type(42))
print("int('100'):", int("100"))
print("str(42):", str(42))
print("float(5):", float(5))

# Math functions
numbers = [3, 1, 4, 1, 5, 9]
print("\\nmin:", min(numbers))
print("max:", max(numbers))
print("sum:", sum(numbers))
print("len:", len(numbers))
print("abs(-7):", abs(-7))
print("round(3.7):", round(3.7))
print("pow(2, 3):", pow(2, 3))

# Sequence functions
print("\\nrange(5):", list(range(5)))
print("sorted:", sorted(numbers))
print("reversed:", list(reversed(numbers)))

# Input/Output
# name = input("Enter name: ")  # Gets user input
print("Hello!")  # Outputs to console