How to Efficiently Update Nested Dictionary Values in Python Without Creating New References?
I'm currently working on a project in Python 3.8 where I need to update values in a nested dictionary without unintentionally creating new references. Here's an example of my dictionary structure: ```python nested_dict = { 'user1': { 'age': 25, 'preferences': {'color': 'blue', 'food': 'pizza'} }, 'user2': { 'age': 30, 'preferences': {'color': 'red', 'food': 'sushi'} } } ``` I want to update the color preference for 'user1' to 'green'. However, I want to ensure that I am modifying the existing dictionary in place rather than creating a new reference. I tried the following: ```python nested_dict['user1']['preferences']['color'] = 'green' ``` This seems to work, but I'm a bit worried about potential side effects, especially if other parts of my code hold references to `nested_dict`. I fear that if I mistakenly assign this to another variable or pass it around, it could lead to unintended behavior. I also read about using the `copy` module for deep copies, but that seems unnecessary for my use case, especially since I just want to update a single value. Additionally, when I print `nested_dict`, I see the updated value as expected: ```python print(nested_dict) # Output: {'user1': {'age': 25, 'preferences': {'color': 'green', 'food': 'pizza'}}, 'user2': {'age': 30, 'preferences': {'color': 'red', 'food': 'sushi'}}} ``` However, is this the best practice for updating nested values? How can I be sure that I'm not causing any issues with references elsewhere in the code? Would using a helper function for the update be a better approach, or am I overcomplicating this? Any insights or best practices would be greatly appreciated!