Unexpected KeyError When Using Python 3.9 with Nested Dictionaries in a Custom Function
I'm working with a `KeyError` when I try to access keys in a nested dictionary using a custom function in Python 3.9. The function is supposed to retrieve values based on a series of keys, but sometimes it fails with specific keys that I expect to exist. Here’s the structure of the nested dictionary I’m working with: ```python my_data = { 'user1': { 'name': 'Alice', 'details': { 'age': 30, 'location': 'New York' } }, 'user2': { 'name': 'Bob', 'details': { 'age': 25 // Note: 'location' key is missing for user2 } } } ``` And here’s my custom function: ```python def get_user_info(user_id, key): try: return my_data[user_id]['details'][key] except KeyError as e: print(f"KeyError: {e} for user_id: {user_id} and key: {key}") return None ``` When I call `get_user_info('user2', 'location')`, I get the following output: ``` KeyError: 'location' for user_id: user2 and key: location ``` The scenario arises because I'm not handling the case where the key might not exist in the nested dictionary. I’ve tried adding a check for the existence of the key before accessing it, but the approach didn’t work as intended: ```python def get_user_info_refined(user_id, key): if user_id in my_data and key in my_data[user_id]['details']: return my_data[user_id]['details'][key] print(f"Key not found for user_id: {user_id} and key: {key}") return None ``` However, I still receive the same `KeyError` under certain conditions. Can anyone suggest a more robust way to handle this situation to avoid runtime exceptions, or clarify what I might be missing about dictionary key access in Python 3.9? I'm working on a service that needs to handle this. Thanks in advance! This is happening in both development and production on Ubuntu 20.04. Thanks, I really appreciate it!