To understand this example, you should have the knowledge of following Python programming topics:
The factorial of a number is the product of all the integers from 1 to that number.
For example, the factorial of 6 (denoted as 6!) is 1*2*3*4*5*6 = 720. Factorial is not defined for negative numbers and the factorial of zero is one, 0! = 1.
# Python program to find the factorial of a number provided by the user. # change the value for a different result num = 7 # uncomment to take input from the user #num = int(input("Enter a number: ")) factorial = 1 # check if the number is negative, positive or zero if num < 0: print("Sorry, factorial does not exist for negative numbers") elif num == 0: print("The factorial of 0 is 1") else: for i in range(1,num + 1): factorial = factorial*i print("The factorial of",num,"is",factorial)
The factorial of 7 is 5040
Note: To test the program, change the value of
num. Try negative numbers as well.
Here, the number whose factorial is to be found is stored in
num and we check if the number is negative, zero or positive using
if...elif...else statement. If the number is positive, we use
for loop and
range() function to calculate the factorial.