Python 3.10: How to efficiently merge dictionaries with nested structures?
I need some guidance on I'm trying to merge two dictionaries in Python 3.10 that contain nested dictionaries, but I'm running into issues with overwriting data instead of combining it as I would like. For example, I have the following two dictionaries: ```python dict_a = { 'key1': {'subkey1': 1, 'subkey2': 2}, 'key2': 3 } dict_b = { 'key1': {'subkey2': 4}, 'key3': 5 } ``` When I attempt to merge them using the `|` operator, I end up with: ```python merged_dict = dict_a | dict_b print(merged_dict) ``` which results in: ```python { 'key1': {'subkey2': 4}, 'key2': 3, 'key3': 5 } ``` This happens because the entire `key1` from `dict_a` is being replaced by `dict_b`. What I actually want is to combine their nested structures so that `subkey1` remains intact and `subkey2` gets updated. I’ve tried using a recursive function to achieve this, but I’m not sure if there’s a more Pythonic way to do it. Here’s my rough attempt: ```python def merge_dicts(dict1, dict2): for key, value in dict2.items(): if key in dict1: if isinstance(value, dict) and isinstance(dict1[key], dict): merge_dicts(dict1[key], value) else: dict1[key] = value else: dict1[key] = value return dict1 result = merge_dicts(dict_a, dict_b) print(result) ``` This works, but I feel like it could be optimized or made cleaner. Are there any built-in methods or libraries that can assist with this type of complex merging? Also, are there any best practices I should be aware of when handling dictionary merges, especially in terms of performance for large datasets? This is part of a larger API I'm building. How would you solve this? My development environment is Windows 10. Any examples would be super helpful.