# Python Program - Find Factorial of a Number

The factorial of a positive integer is the multiplication of all positive integer less than or equal to that number.

factorial of number n = n! = n(n-1)(n-2)...1

### For Example:

5! = 5 × 4 × 3 × 2 × 1 = 120

4! = 4 × 3 × 2 × 1 = 24

### Method 1: Using Recursive method

In the example below, a recursive function called factorial() is used to calculate factorial of a number.

```def factorial(x):
if x == 0 or x ==1:
return 1
else:
return x*factorial(x-1)

print("10! = ", factorial(10))
print("6! = ", factorial(6))
```

The above code will give the following output:

```10! =  3628800
6! =  720
```

### Method 2: Using Iterative method

The factorial of a number can also be calculated using iterative method.

```def factorial(x):
final = 1
for i in range(x,1,-1):
final = final * i
return final

print("10! = ", factorial(10))
print("6! = ", factorial(6))
```

The above code will give the following output:

```10! =  3628800
6! =  720
```

### Method 3: Using Short-hand If-else method (Ternary operator)

In the example below, the factorial of a number is calculated using short-hand if-else method.

```def factorial(x):
y = 1 if (x == 0 or x ==1) else x * factorial(x-1)
return y

print("10! = ", factorial(10))
print("6! = ", factorial(6))
```

The above code will give the following output:

```10! =  3628800
6! =  720
```

5