Recursion in Python: Factorial with Debugging Explained

What is Recursion? Recursion is a technique where a function calls itself to solve a problem step by step. Instead of using loops, recursion breaks a problem into smaller subproblems. Factorial Using Recursion Factorial of a number means: 5! = 5 × 4 × 3 × 2 × 1 = 120 Python Code def factorial ( n ): if n == 1 : return 1 return n * factorial ( n - 1 ) print ( factorial ( 5 )) Debugging the Code (Step-by-Step Execution) Let’s trace what happens when we call: factorial ( 5 ) Function Calls factorial(5) = 5 * factorial(4) factorial(4) = 4 * factorial(3) factorial(3) = 3 * factorial(2) factorial(2) = 2 * factorial(1) factorial(1) = 1 (Base Condition) Returning Values (Backtracking) factorial(2) = 2 * 1 = 2 factorial(3) = 3 * 2 = 6 factorial(4) = 4 * 6 = 24 factorial(5) = 5 * 24 = 120 Understanding the Debugging Flow Recursion has 2 important parts: 1. Base Case if n == 1 : return 1 Stops the function from running forever. 2. Recursive Case return n * factorial ( n - 1 ) Function calls itsel