# my_package/my_module.py

def greet(name):
    """
    Returns a greeting message.
    
    Parameters:
    name (str): The name of the person to greet.

    Returns:
    str: Greeting message.
    """
    return f"Hello, {name}!"

def add(a, b):
    """
    Returns the sum of two numbers.
    
    Parameters:
    a (int or float): The first number.
    b (int or float): The second number.

    Returns:
    int or float: The sum of the two numbers.
    """
    return a + b

def subtract(a, b):
    """
    Returns the difference between two numbers.
    
    Parameters:
    a (int or float): The first number.
    b (int or float): The second number.

    Returns:
    int or float: The difference between the two numbers.
    """
    return a - b
