# factorial program in python

In this post, we will see how to find factorial of a number in python.

Factorial of number is product of all integer from 1 to that number.

**For example:**

Factorial of 4 is : 1*2*3*4=24

There are two ways to do it.

- Using iteration
- Using recursion

## Using iteration

Here is simple python program to find factorial of a given number.

```
num=4
#uncomment below line to take input from user
#num =int(input("Enter number:"))
factorial=1
while(num!=0):
factorial*=num
num=num-1
print(factorial)
```

**Output:**

24

**Explanation:**

- Intialize facorial to 1
- Iterate until num is not equal to zero
- Multiply number by factorial by num and decrement the num.

## Using Recursion

You can find factorial of the program using recursion as well.

```
# Python program to find the factorial of a number using recursion
def factorial(num):
if(num == 1):
return num
else:
return num*factorial(num-1)
num=4
#uncomment below line to take input from user
#num =int(input("Enter number:"))
print(factorial(num))
```

**Output:**

24

That’s all about finding factorial of given number in java.