In this simple python program, we need to find the sum of natural numbers. It's a number python program.

To understand this example, you should have knowledge of the following Python programming topics:

This python program is to print the sum of n natural numbers. Natural numbers are positive whole numbers like** 1, 2, 3 ...** some are saying zero is not a natural number, and some argue that zero is also a natural number. So natural numbers can be defined as a set of whole numbers, which are **positive**, including zero.

In this python program, we need to calculate the sum of N natural numbers in python and print the result. So we have to accept user input and store that in a variable. Then we use an if condition to check the number is greater than zero. if not Break the program. In the `else`

part, we have to use a while loop in python till the number is greater than zero and add each number to the **sum **and reduce the number by one to get the next lower number until the number reaches zero. Finally, print the **sum **after all the iteration of the `while loop`

is over.

**STEP 1:** Accept the user's input using input and convert the string to an integer using **int()** in the python programming language.

**STEP 2:** Use the `if`

condition to check the entered number is less than zero and print enter the positive number.

**STEP 3:** Use the `else`

condition and initialize a **sum **variable to **zero**.

**STEP 4:** Start a `while loop`

in python language, where a number greater than zero condition means the loop will continue until the number equal to zero.

**STEP 5:** Calculate the sum as **sum = sum + num** and then reduce the **num **by **one**.

**STEP 6:** print the **sum **variable using the print statement in the python program.

` ````
num = int(input("Enter a value of n: "))
if num < 0:
print("Enter a positive number")
else:
sum = 0
while(num > 0):
sum += num
num -= 1
print("The sum is",sum)
```

Enter a value of n: 5 The sum of N natural numbers is 15