 # Factorial program in python

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Tags:- Python # Python | Program to find factorial of a number

This is an example of how to find the factorial of a number in python.

The factorial of a number is a product of all the positive integers less than or equal to that number.
For example, the factorial of 5 is  5x4x3x2x1 = 120

Factorial is not defined for negative integers, and the factorial of zero is one, 0! = 1.

Check here for factorial recursive way

``````n = int(input('Enter no.:'))
fact = 1
for i in range(1,n+1):
fact *= i
print(fact)``````

Output for the above code

```>>>
====================== RESTART: E:\py\factorial.py ======================
Enter no.:5
120```

let's modify the code to handle number less than or equal to zero

``````n = int(input('Enter no.:'))
fact = 1

if n < 0:
print(f"Sorry, factorial does not exist for {n}, negative number")
elif n == 0:
print("The factorial of 0 is 1")
else:
for i in range(1,n+1):
fact *= i

print(fact)``````

Output for the above code

```>>>
====================== RESTART: E:\py\factorial.py ======================
Enter no.:5
120
>>>
====================== RESTART: E:\py\factorial.py ======================
Enter no.:0
The factorial of 0 is 1
>>>
====================== RESTART: E:\py\factorial.py ======================
Enter no.:-5
Sorry, factorial does not exist for -5, negative number```