Functions in Python

What is Function?

• Block of programming statements is called a function which designed to perform a certain task.
• Reusing the same code is required many times within a same program can be defined as functions.
• We write the things we have to do repeatedly in a function then call it where ever required.
• We will see the built in functions like len() in coming concepts.
• To define a function, Python provides the def keyword.
• Python gives you many built-in functions like print(), etc.

Syntax: “def” is a keyword which is used to define functions in Python.

def  identity(arguments) :
	……
	Logic
	……

Example snippet:

def  add(a, b):
	c=a+b
	return c

Calling or Invoking the Function: Every function consists

1. Function definition:
   • Function definition is a block.
   • Definition contains logic to perform the task.
   • Function definition will not execute automatically in the program.
2. Function call:
   • It is a single statement.
   • It used to access the function definition.

Definition syntax :

def  add(a, b):
	c=a+b
	return c

Call syntax :

res = add(10,20)

• General example to understand the concept of function calling.
• Television program contains lot of functionality but executes only when we control the Television from another program called Controller.

• A simple function is defined here with one line of logic.
• Return statement is optional in this code.
• Return statement represents the end of function to programmers.

def fun():
    print("First function")
    return

fun() #calling