Functions in Python: Basic Concepts

Introduction

In Python, functions are like little helpers that perform specific tasks. They make code organized and reusable. Let's explore two types of functions: those without parameters and those with two parameters. We'll also cover functions with and without a return value.

Functions Without Parameters

def say_hello():
    """This function prints a simple greeting."""
    print("Hello, world!")

# Function Call
say_hello()

def say_hello():: Declares a function named say_hello without parameters.
print("Hello, world!"): Code inside the function that prints a greeting.

Functions with Two Parameters

def add_numbers(x, y):
    """This function adds two numbers and prints the result."""
    result = x + y
    print("Sum:", result)

# Function Call
add_numbers(5, 3)

def add_numbers(x, y):: Declares a function named add_numbers with two parameters (x and y).
result = x + y: Performs addition inside the function.
print("Sum:", result): Prints the result.

Functions with Return Value

def multiply_numbers(a, b):
    """This function multiplies two numbers and returns the result."""
    result = a * b
    return result

# Function Call
product = multiply_numbers(4, 7)
print("Product:", product)

def multiply_numbers(a, b):: Declares a function named multiply_numbers with two parameters.
return result: Returns the multiplication result.
product = multiply_numbers(4, 7): Calls the function and assigns the result to product.
print("Product:", product): Prints the product.

Functions Without Return Value

def greet_user():
    """This function greets the user without returning a value."""
    print("Hey there! Welcome!")

# Function Call
greet_user()

def greet_user():: Declares a function named greet_user without a return value.
print("Hey there! Welcome!"): Prints a friendly greeting.

More examples

Example 1: Greeting Function

def greet_user():
    """This function greets the user without returning a value."""
    print("Hey there! Welcome!")

# Function Call
greet_user()

Explanation: This function says a friendly greeting.
Example Message: "Hey there! Welcome!"

Example 2: Calculator Function

def multiply_numbers(a, b):
    """This function multiplies two numbers and returns the result."""
    result = a * b
    return result

# Function Call
product = multiply_numbers(4, 7)
print("Product:", product)

Explanation: This function multiplies two numbers.
Example Message: "Product: 28"

These basic functions help keep code organized and are easy to understand. Functions without parameters perform specific actions, while functions with parameters allow customization. Functions with return values provide results that can be used in other parts of the code.