Lecture 50:- Factorial In Python

In Python, you can calculate the factorial of a non-negative integer using a recursive function or a loop. The factorial of a non-negative integer n is the product of all positive integers less than or equal to n.

1. Using Recursive Function:

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def factorial_recursive(n):    if n == 0 or n == 1:        return 1    else:        return n * factorial_recursive(n - 1) # Example usage: num = 5 result = factorial_recursive(num) print(f"The factorial of {num} is: {result}")

Output:

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The factorial of 5 is: 120

1. Using Loop:

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def factorial_loop(n):    result = 1    for i in range(1, n + 1):        result *= i    return result # Example usage: num = 5 result = factorial_loop(num) print(f"The factorial of {num} is: {result}")

Output:

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The factorial of 5 is: 120

In both examples, the function factorial_recursive() and factorial_loop() calculate the factorial of a given non-negative integer n. In the recursive approach, the function calls itself to calculate the factorial. In the loop approach, the function uses a for loop to iterate from 1 to n and continuously multiplies the result by the current value of i to calculate the factorial.

When you call either of the functions with num = 5, it will calculate the factorial of 5, which is 120, and print the result. You can replace num with any non-negative integer to calculate its factorial.