Recursion

When a function calls itself, then this is called recursion.
These are some of the script which are illustrating the use of recursion.

Script1: Write an script to print natural numbers from 1 to n in descending order using recursion, the value of n will be entered by the user.

def printnatno(n):
    if n==0:
        return
    else:
        print(n)
        printnatno(n-1)

n=int(input("Enter the value of n "))
printnatno(n)

Script2: Write a function to calculate the factorial of a number using recursion.

def calfact(n):

    if n==0 or n==1:

        return 1

    else:

        return n*calfact(n-1)

n=int(input("Enter the number "))

ans=calfact(n)

print("The factorial of {} is {}".format(n,ans))