This program takes an input number from user and finds the factorial of that number using a recursive function. Factorial of a number is the product of an integer and all the integers below it, for example the factorial of 4 is 4*3*2*1 = 24.
Program to find factorial
In this program we have defined a function factorial(). This function takes a number as an argument and finds the factorial of it.
# This Python Program finds the factorial of a number
def factorial(num):
"""This is a recursive function that calls
itself to find the factorial of given number"""
if num == 1:
return num
else:
return num * factorial(num - 1)
# We will find the factorial of this number
num = int(input("Enter a Number: "))
# if input number is negative then return an error message
# elif the input number is 0 then display 1 as output
# else calculate the factorial by calling the user defined function
if num < 0:
print("Factorial cannot be found for negative numbers")
elif num == 0:
print("Factorial of 0 is 1")
else:
print("Factorial of", num, "is: ", factorial(num))
Output:
