CodexBloom - Programming Q&A Platform

Handling TypeError in Python 3.10 when unpacking tuple from a list of dictionaries

👀 Views: 377 đŸ’Ŧ Answers: 1 📅 Created: 2025-06-10
python tuple error-handling Python

I'm testing a new approach and I need some guidance on I keep running into I've searched everywhere and can't find a clear answer... After trying multiple solutions online, I still can't figure this out. I'm currently working on a Python 3.10 project where I'm trying to extract specific values from a list of dictionaries and unpack them into variables. However, I'm working with a `TypeError` when trying to unpack the values. Here's the relevant part of my code: ```python data = [ {'name': 'Alice', 'age': 30}, {'name': 'Bob', 'age': 25}, {'name': 'Charlie'}, # Missing age key ] for entry in data: try: name, age = entry['name'], entry['age'] print(f'{name} is {age} years old.') except TypeError as e: print(f'behavior unpacking entry: {e}') print('Skipping entry due to missing age.') ``` When I run this code, I get the following behavior: ``` behavior unpacking entry: want to unpack non-iterable NoneType object Skipping entry due to missing age. ``` It seems like the offending line is `name, age = entry['name'], entry['age']`, but I'm unsure why it fails for the dictionary missing the `age` key. I thought that using `entry['age']` would simply yield a `None` value instead of causing a `TypeError`. I tried adding a check to see if the key exists before unpacking, but that led to different issues with the unpacking itself. Is there a better way to handle this situation without running into unpacking errors? Also, is there a best practice for dealing with optional dictionary keys in Python? Any insights would be greatly appreciated! Thanks in advance! For context: I'm using Python on macOS. What's the best practice here? The stack includes Python and several other technologies. Any ideas what could be causing this? I'm coming from a different tech stack and learning Python. The project is a desktop app built with Python.