advanced patterns When Modifying Function Arguments in Python 3.9
I've searched everywhere and can't find a clear answer. Hey everyone, I'm running into an issue that's driving me crazy. I'm stuck on something that should probably be simple. I'm running into an scenario with Python 3.9 where modifying a mutable argument inside a function doesn't seem to reflect outside the function as expected. Here's a simplified version of the code that demonstrates the question: ```python def modify_list(input_list): input_list.append('new_item') return input_list my_list = [1, 2, 3] returned_list = modify_list(my_list) print('Returned List:', returned_list) # Should print [1, 2, 3, 'new_item'] print('Original List:', my_list) # Should also print [1, 2, 3, 'new_item'] ``` However, when I run this, I see that the `my_list` is indeed modified, but if I try to do something like this instead: ```python def reset_list(input_list): input_list = [0, 0, 0] return input_list my_list = [1, 2, 3] returned_list = reset_list(my_list) print('Returned List:', returned_list) # Should print [0, 0, 0] print('Original List:', my_list) # Should still print [1, 2, 3] ``` In this case, it looks like the original `my_list` remains unchanged after calling `reset_list`. I expected it to be modified as well. I've looked into mutable vs immutable types, and while I understand that lists are mutable, I need to grasp why reassigning `input_list` does not affect `my_list`. Is this related to the way Python handles variable assignment or scope? Any insights or best practices to handle similar scenarios would be greatly appreciated! For context: I'm using Python on Windows. My development environment is macOS. Am I missing something obvious? My development environment is macOS. Am I missing something obvious?