KeyError when Merging Two Dictionaries in Python with Nested Structures
I'm trying to merge two dictionaries in Python where each dictionary contains nested structures, but I keep running into a `KeyError`. Here’s a simplified version of my code: ```python dict_a = { 'key1': {'subkey1': 1, 'subkey2': 2}, 'key2': {'subkey1': 3} } dict_b = { 'key1': {'subkey2': 4, 'subkey3': 5}, 'key2': {'subkey1': 6, 'subkey2': 7} } merged_dict = {} for key in dict_a.keys(): merged_dict[key] = dict_a[key] merged_dict[key].update(dict_b.get(key, {})) print(merged_dict) ``` When I run this, I get a `KeyError: 'key2'` on the line where I'm calling `update()`. I believe it's because `dict_b` may not have all the keys that are present in `dict_a`, but I'm using `get()` to avoid that scenario. I also tried adding a check before the `update()` call like this: ```python if key in dict_b: merged_dict[key].update(dict_b[key]) ``` But I still get the same behavior. I suspect that the nested structure might be causing the question. How can I properly merge these dictionaries without working with a `KeyError`? Any best practices or patterns to handle this scenario would be greatly appreciated. I'm using Python 3.9. Any help would be greatly appreciated!