# Python Program Factorial Three Versions

By | July 23, 2019

Python Program Factorial Three Versions – This Python tutorial explains three different source codes of the Python factorial program.

Write a program that asks the user for a number and prints out the factorial of that number:

1. Using  factorial() function of math module
2. Using for loop
3. Using while loop Python Program Factorial using Three different methods

The Python has a math module. This math module contains a factorial() function that takes a positive integer as argument and returns the factorial of that number.

### How to use Python factorial() function

We will use factorial() function after importing math module in our Python program.

## Python Program Factorial Three Versions

### The Source code of the Python factorial Program using factorial function

```# Write a program that asks the user
# to enter a number.
# The program should display the factorial
# of that number

# Author: www.EasyCodeBook.com (c)

from math import factorial
num = int(input('Enter a number to find its factorial:'))
fact = factorial(num)
print('The Factorial of', num,'is:',fact)
```
```The output is:
Enter a number to find its factorial:4
The Factorial of 4 is: 24
```

### Python Factorial Program using for loop

```# Write a program that asks the user
# to enter a number.
# The program should display the factorial
# of that number using for loop.

# Author: www.EasyCodeBook.com (c)

num = int(input('Enter a number to find its factorial:'))
fact = 1
for i in range(1,num+1):
fact = fact * i
print('The Factorial of', num,'is:',fact)
```
```The output is as follows:
Enter a number to find its factorial:5
The Factorial of 5 is: 120
```

### Python Factorial program using while loop

```# Write a program that asks the user
# to enter a number.
# The program should display the factorial
# of that number using while loop.

# Author: www.EasyCodeBook.com (c)

num = int(input('Enter a number to find its factorial:'))
i = fact = 1
while i<=num:
fact = fact * i
i+=1
print('The Factorial of', num,'is:',fact)
```
```The output of factrial program using while loop is:
Enter a number to find its factorial:6
The Factorial of 6 is: 720
```