Python Program to Find Factorial of a Number

Python Program to Find Factorial of a Number

Python programs to find factorial of number example; In this tutorial, you will learn how to find factorial of given number or user-inputted number in python using while loop, for loop and recursion fuction.

Factorial, in mathematics, the product of all positive integers less than or equal to a given positive integer and denoted by that integer and an exclamation point. Thus, factorial seven is written 7!, meaning 1 × 2 × 3 × 4 × 5 × 6 × 7. Factorial zero is defined as equal to 1.

Find the Factorial of a Number in Python

Let’s use the following algorithm to write a program to calculate/find the factorial of a number in python:

  • Python Program find factorial using using While Loop
  • Factorial of a number in python using for loop
  • Factorial of a number in python using recursion

Python Program find factorial using using While Loop

Follow the below steps and write a python program to find factorial of a number using while loop

  • Take input from the user
  • Define fact variable
  • Iterate while loop and find factorial of given number and store it
  • Print factorial
num = int(input("enter a number: "))
 
fact = 1
i = 1
 
while i <= num:
 fact = fact * i
 i = i + 1
 
print ("Factorial of the number %d is %d" %(num, fact))

Output

enter a number: 5
Factorial of the number 5 is 120

Factorial of a number in python using for loop

Follow the below steps and write a python program to find factorial of a number using for loop

  • Take input from the user
  • Define fact variable
  • Iterate for loop and calculate factorial of number
  • Print the final result
#Python program to print factorial of a number
num = int(input("Enter the number: "))
fact = 1

#iterating through the num value
for i in range (1, num+1):
    fact = fact*i

#printing the output
print ("Factorial of the number %d is %d" %(num, fact))

Output

Enter the number: 10
Factorial of the number 10 is 3628800

Factorial of a number in python using recursion

Follow the below steps and write a python program to find factorial of a number using recursion

  • Define a function to calculate factorial of given number
  • Take input from the user
  • Use if else statement to check input number
  • Call above define factorial function
  • Print the final result
# Factorial of a number using recursion

def recur_factorial(n):
   if n == 1:
       return n
   else:
       return n*recur_factorial(n-1)

num = int(input("Enter the number: "))

# check if the number is negative
if num < 0:
   print("Sorry, factorial does not exist for negative numbers")
elif num == 0:
   print("The factorial of 0 is 1")
else:
   print("The factorial of", num, "is", recur_factorial(num))

Output

Enter the number: 6
The factorial of 6 is 720

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AuthorAdmin

My name is Devendra Dode. I am a full-stack developer, entrepreneur, and owner of Tutsmake.com. I like writing tutorials and tips that can help other developers. I share tutorials of PHP, Python, Javascript, JQuery, Laravel, Livewire, Codeigniter, Node JS, Express JS, Vue JS, Angular JS, React Js, MySQL, MongoDB, REST APIs, Windows, Xampp, Linux, Ubuntu, Amazon AWS, Composer, SEO, WordPress, SSL and Bootstrap from a starting stage. As well as demo example.

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