In this tutorial you will learn about the Python Program to Find the Factorial of a Number and its application with practical example.
In this tutorial, we will learn to create a Python Program to Find the Factorial of a Number using Python programming.
Before starting with this tutorial we assume that you are best aware of the following Python programming topics:
- Basic Input and Output
- Basic Python programming.
- Python if-else statements.
- Python Loop.
What is Factorial ?
Factorial of a given number ‘n’ is the product of all its positive integers numbers.
Example: The factorial of 5 is 120.
5! = 5 * 4 * 3 * 2 *1
5! = 120.
Python Program to Find the Factorial of a Number
In this program we will find factorial of a given number . We would first declared and initialized the required variables. Next, we would prompt user to input a number .Later we will Find Factorial.
# python program to find factorial of given number
number = int(input("enter any number"))
#initialize fact to 1
fact = 1
# checking if the given number is negative...
if number < 0:
print("Factorial does not exist of negative numbers")
# if number is zero
elif number == 0:
print("The factorial of 0 is 1")
for i in range(1,number + 1):
fact = fact*i
print("The factorial of",number,"is",fact)
In the above program, we have first declared and initialized a set variables required in the program.
- number = it will hold entered number.
- fact = it will hold a factorial of a number.
- i = for iteration.
In this program, First we declare and initiate variables and later we will find factorial of a given number.
First of all we take a number as input from user and store the value in variable ‘number’. and fact to one ( fact=1).
And now we will check first that the given number is greater than 1 or not ( number< 0 ) if not we show message in below.
Now we will check condition for number is equal to zero ( number ==0 ).
As we know that if number is zero it’s factorial is one and after all his we finally find factorial of a given number.
In this program user is promoted to enter a positive integer as show in image above , the for loop runs from ‘1 to number’. In every iteration , fact is multiplied with i ( fact=fact*i ) and after all iterations we will get the value of factorial of number.