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Python | Find factorial of a given number (2 different ways)
Here, we are going to implement logic to find factorial of given number in Python, there are two methods that we are going to use 1) using loop and 2) using recursion method.
Submitted by IncludeHelp, on August 09, 2018
Given a number and we have to find its factorial in Python.
Example:
Input:
Num = 4
Output:
Factorial of 4 is: 24
1) Method 1: Using loop
# Code to find factorial on num
# number
num = 4
# 'fact' - variable to store factorial
fact =1
# run loop from 1 to num
# multiply the numbers from 1 to num
# and, assign it to fact variable
for i in range (1,num+1) :
fact = fact*i
# print the factorial
print "Factorial of {0} is: {1} ".format (num, fact)
Output
Factorial of 4 is: 24
2) Method 2: by creating a function using recursion method
To find the factorial, fact() function is written in the program. This function will take number (num) as an argument and return the factorial of the number.
# function to calculate the factorial
def fact (n):
if n == 0:
return 1
return n * fact (n - 1)
# Main code
num = 4
# Factorial
print "Factorial of {0} is: {1} ".format (num, fact(num))
Output
Factorial of 4 is: 24