What are Functions ?

                             A function in Python is a reusable block of code that performs a specific task.
                             Instead of writing the same code again and again, we can place it inside a function and call it whenever needed.

Features :
             Reusability - A function allows you to write code once and use it multiple times.
             Modularity - Functions divide a big program into smaller logical parts.
             Readability - Functions give meaningful names to operations.
             Abstraction - Functions hide internal logic and expose only purpose.


Creation :
Python
def function_name(): statement(s)

def → keyword to define a function

function_name → name of the function

() → parentheses (parameters go here)

: → indicates block start

indented statements → function body


Function Names :

  • A function name must start with a letter or underscore
  • A function name can only contain letters, numbers, and underscores
  • Function names are case-sensitive (myFunction and myfunction are different)

Example :

Python 
def greet(): print("Welcome to Python!") greet() #output 'Welcome to Python!'