Function for factorial in Python

Question

How do I go about computing a factorial of an integer in Python?

Answer 1

The factorial of a number is defined as:

factorial(n)=n * factorial(n-1)
or

factorial(n)=n∗(n−1)∗(n−2)...∗1

In Python, there are two approaches to computing the factorial of a number:

Iterative Method:

The iterative approach works by setting a base value to 1. For each loop, the method multiplies to the base value until the for loop finishes and you get the final factorial value.
Recursive Method:

The recursive approach is when a function calls itself again until it reaches a stop condition. It is divided into two sections:

Basic scenario
The recursion comes to an end here.
Case Recursive
This occurs when a function calls itself again and over until the base condition is met.
factorial(4)=4
*factorial(3) \sfactorial(4)=4
∗factorial(3) \sfactorial(3)=3
*factorial(2) \sfactorial(3)=3
∗factorial(2) \sfactorial(2)=2
*factorial(1) \sfactorial(2)=2
∗factorial(1) \sfactorial(1)=1
*factorial(0) \sfactorial(1)=1
∗factorial(0)