Python on the go - Revision of Functions

A function is a block of code which performs a computation. They can be reused in a program.
Here are some functions that can be used on lists

https://docs.python.org/2/tutorial/datastructures.html

These are inbuilt functions.  Certain functions like maths functions can be imported into the program by typing

from math import* 

We can also create our own functions. The 'Hello World' program can be written in a function as shown below.

def hello():
      print  "Hello World"

To call and run the function type  hello()  in the python shell