# Support Our Site

To ensure we can continue delivering content and maintaining a free platform for all users, we kindly request that you disable your adblocker. Your contribution greatly supports our site's growth and development.

# Python Program Find Factorial Of A Number

The factorial of a number is the product of all the integers from 1 to that number. Mathematically, the formula for the factorial is as follows. If n is an integer greater than or equal to 1, then factorial of n is,

`` (n!) = 1*2*3*4....*n``

Also, the factorial value of 0 is equal to 1 and the factorial values for negative integers are not defined.

## Problem Definition

Create a Python Program to find the factorial of the user-provided number.

## Factorial of a number using For Loop

``````num = int(input("Enter the Number :"))
fact = 1
if num < 0:
print("Factorial of negative number is not defined")
else:
for i in range(1,num+1):
fact *= i
print("Factorial of {} is {}".format(num, fact))``````

#### Output

``````Enter the Number :
7
Factorial of 7 is 5040``````

In this program first, we are taking input from the keyboard using the `input()` function then we have a conditional statement for negative inputs since factorial of a negative number doesn't exist.

Then we have a for loop in range 1 to the number itself inside the loop we are simply iterating over loop variable `i` and multiplying it with the `fact` variable defined above. In the end, we are simply printing out the result using string formatting.

## Factorial of a number using While Loop

The same program can be implemented using a while loop as follows,

``````num = int(input("Enter the Number :"))
fact = 1i = 1
if num < 0:
print("Factorial of negative number is not defined")
else:
while(i<=num):
fact *= i
i += 1
print("Factorial of {} is {}".format(num, fact))``````

#### Output

``````Enter the Number :6
Factorial of 6 is 720``````

## Factorial function

You can wrap the above code in a function as follows,

``````def factorial(n):
result = 1
for i in range(1, n + 1):
result *= i
return result

# Example usage
number = int(input("Enter a number: "))
print(f"The factorial of {number} is {factorial(number)}")``````

## Factorial of a number using recursion

Alternatively, you can use recursion to calculate the factorial:

``````def factorial(n):
if n == 0 or n == 1:
return 1
else:
return n * factorial(n - 1)

# Example usage
number = int(input("Enter a number: "))
print(f"The factorial of {number} is {factorial(number)}")``````

## Factorial of a number using math module

Since Python always has a better way of doing things, it comes with a built-in solution for computing factorial of a number.

``````import math

number = int(input("Enter a number: "))
factorial_result = math.factorial(number)

print(f"The factorial of {number} is {factorial_result}")``````

#### Output

``````Enter the Number :5
Factorial of 5 is 120``````

The `math` library which ships with Python has a `factorial()` method that returns the factorial of the provided number.

PROGRAMS

# Latest Articles

Latest from djangocentral

## How to Use Subquery() in Django With Practical Examples

In the realm of web development, Django stands as a powerful and versatile framework for building robust applications. One of the key aspects of developing efficient and optimized web applications is handling database queries effectively. In this article…

## DRF Serializer: Handling OrderedDict and Converting It to a Dictionary or JSON

In Django Rest Framework (DRF) tests, when you access serializer.data, you might encounter an OrderedDict instead of a regular dictionary. This behavior is intentional and reflects the design of DRF's serialization process.Understanding the Problem The u…

## Django Rest Framework CheetSheet: Mastering API Development

Django Rest Framework (DRF) is a powerful toolkit that makes building robust and scalable web APIs with Django a breeze. Whether you're a seasoned Django developer or a newcomer, having a comprehensive cheat sheet at your disposal can be a game-changer. …