Handling TypeError when accessing array elements in a recursive function in Python
I'm attempting to set up I've tried everything I can think of but I've been struggling with this for a few days now and could really use some help. I've looked through the documentation and I'm still confused about I'm attempting to set up I'm a bit lost with I've tried everything I can think of but I've been banging my head against this for hours....... I tried several approaches but none seem to work. I'm trying to implement a recursive function in Python that processes a nested array of integers and returns the sum of all elements. However, I'm working with a `TypeError` when trying to access elements in certain cases. Here's the code I've written: ```python def recursive_sum(arr): total = 0 for item in arr: if isinstance(item, list): total += recursive_sum(item) else: total += item return total nested_array = [1, [2, 3], [4, [5, 6]], 7] result = recursive_sum(nested_array) print(result) ``` When I run this with the above nested array, it works perfectly. However, when I pass in an array that includes a `None` value, like this: ```python nested_array_with_none = [1, [2, None], [4, [5, 6]], 7] result = recursive_sum(nested_array_with_none) print(result) ``` I get the following behavior: `TypeError: 'NoneType' object is not iterable`. I assumed that the check with `isinstance(item, list)` would prevent this since `None` is not a list, but it seems I need to handle this edge case better. What’s the best way to modify my function to avoid this behavior? I want to ensure that `None` values are simply ignored and don't break the recursion. I've thought about adding an additional check before the `else` statement, but I'm not sure how to implement it cleanly. Any suggestions? This is part of a larger web app I'm building. Is there a better approach? For context: I'm using Python on Ubuntu. For reference, this is a production mobile app. This is happening in both development and production on Ubuntu 20.04. Any suggestions would be helpful. I'm working with Python in a Docker container on Debian. What's the best practice here? I'm working on a CLI tool that needs to handle this. Cheers for any assistance! Cheers for any assistance! Any help would be greatly appreciated! For reference, this is a production mobile app. Thanks for your help in advance!