In this article, you'll learn to find the factorial of a number and display it.

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

The factorial of a number is the product of all the integers from 1 to that number.

For example, the factorial of 6 (denoted as 6!) is 1*2*3*4*5*6 = 720. Factorial is not defined for negative numbers and the factorial of zero is one, 0! = 1.

# Python program to find the factorial of a number provided by the user. # change the value for a different result num = 7 # uncomment to take input from the user #num = int(input("Enter a number: ")) factorial = 1 # check if the number is negative, positive or zero if num < 0: print("Sorry, factorial does not exist for negative numbers") elif num == 0: print("The factorial of 0 is 1") else: for i in range(1,num + 1): factorial = factorial*i print("The factorial of",num,"is",factorial)

**Output**

The factorial of 7 is 5040

**Note:** To test the program, change the value of `num`

. Try negative numbers as well.

Here, the number whose factorial is to be found is stored in `num`

and we check if the number is negative, zero or positive using `if...elif...else`

statement. If the number is positive, we use `for`

loop and `range()`

function to calculate the factorial.