Find Factorial of a Number

Theory:

The factorial of a non-negative integer n is the product of all positive integers less than or equal to n.

Python Code:

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

# Taking input from the user
number = int(input("Enter a number to find its factorial: "))
print("Factorial of", number, "is", factorial(number))

Example:

Enter a number to find its factorial: 5

Factorial of 5 is 120

Code Explanation:

The function factorial(n) calculates the factorial of the given non-negative integer n.

If n is equal to 0, the factorial is 1. Otherwise, it recursively calculates the factorial by multiplying n with the factorial of n-1.

The example usage section demonstrates how to take input from the user, calculate the factorial, and print the result.