Functions is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to define a Function

def function_name(parameters):
    #code

How to call a Function

function_name (parameters)

Example

def greeting(name):
    print("Happy learning" + " " + name + "!")

greeting("foo")

Result of the above sample program is:

Happy learning foo!