implementing Nested Dictionary Updates in Python When Handling API Responses
I'm working with a nested dictionary in Python, where I'm trying to update values based on an API response. The API sends back a JSON object that I parse into a dictionary structure. However, I'm running into issues where the updates are not happening as expected. For instance, when I try to update a nested key, it seems like the existing values are being overwritten, and I'm not able to retain the previous data. Here’s a simplified version of my code that demonstrates the scenario: ```python import json # Initial nested dictionary my_dict = { 'user1': {'name': 'Alice', 'age': 30}, 'user2': {'name': 'Bob', 'age': 25} } # Simulated API response api_response = '''{ "user1": {"age": 31}, "user3": {"name": "Charlie", "age": 22} }''' # Parsing API response to dictionary response_dict = json.loads(api_response) # Update my_dict with values from response_dict for user, attributes in response_dict.items(): if user in my_dict: my_dict[user].update(attributes) # This is where the question occurs else: my_dict[user] = attributes print(my_dict) ``` When I run this code, I expected `my_dict` to be updated correctly with user1's new age, but the output shows that there's a discrepancy. The expected output should be {'user1': {'name': 'Alice', 'age': 31}, 'user2': {'name': 'Bob', 'age': 25}, 'user3': {'name': 'Charlie', 'age': 22}}, but I get: ``` {'user1': {'age': 31}, 'user2': {'name': 'Bob', 'age': 25}, 'user3': {'name': 'Charlie', 'age': 22}} ``` It seems that I'm losing the original `name` value for `user1` and I'm not sure why. I have tried using `.setdefault()` as well, but it didn’t resolve the scenario. Is there a correct approach to update nested dictionaries without losing existing values in Python? I'm currently using Python 3.8. Any insights would be greatly appreciated.