Functions in Python: A Beginner’s Guide with Examples

Functions in Python

1. Defining Functions
 A function in Python is a block of reusable code that performs a specific
task. You define a function using the def keyword.

Syntax:

def function_name(parameters):
# Code to execute
return result # Optional, used to return a value from the function


Example:

def greet():
print("Hello, World!")

greet() # Calling the function

Output:


Hello, World!


In this example:

 def is the keyword used to define a function.
 greet is the function name.
 The parentheses () are used for parameters (in this case, there are none).
 The print statement is the code that runs when the function is called.

, 2. Function Parameters
 Functions can take parameters (also called arguments) that allow you to
pass data into the function.

Syntax:

def function_name(parameter1, parameter2):
# Code that uses the parameters
return result

Example:

def add_numbers(a, b):
return a + b

result = add_numbers(3, 5)
print(result) # Output: 8

In this case:

 a and b are parameters.
 The function returns the sum of a and b.



3. Default Parameters
 You can set default values for parameters in case no value is passed during
the function call.

Syntax:

def greet(name="Guest"):
print(f"Hello, {name}!")



Example: