Why is my for loop skipping iterations when modifying a dictionary in Python 3.10?
I'm integrating two systems and I've tried everything I can think of but Hey everyone, I'm running into an issue that's driving me crazy... I've been struggling with this for a few days now and could really use some help. I'm encountering an issue with a `for` loop where it seems to skip certain iterations when I modify a dictionary during the loop. The dictionary contains user data, and I'm trying to filter out users based on their status while iterating through it. Here’s a snippet of what I’m doing: ```python users = { 'user1': 'active', 'user2': 'inactive', 'user3': 'active', 'user4': 'inactive' } for user, status in users.items(): if status == 'inactive': del users[user] # Trying to remove inactive users print(f'Removed {user}') else: print(f'{user} is active') ``` When I run this code, I expect to see that both `user2` and `user4` are removed, but it only prints `Removed user2`, and then it prints `user3 is active` and skips `user4`. I thought modifying the dictionary while iterating would affect the loop, but I didn't expect it to skip entries completely. I’ve also tried using a list of keys to delete afterwards, like this: ```python users = { 'user1': 'active', 'user2': 'inactive', 'user3': 'active', 'user4': 'inactive' } inactive_users = [user for user, status in users.items() if status == 'inactive'] for user in inactive_users: del users[user] print(f'Removed {user}') ``` This approach works fine, but I’d like to understand why the first method behaves the way it does. Is there something in Python 3.10 that affects the iteration behavior when modifying the dictionary? Any insights on best practices for handling such scenarios would be greatly appreciated! I'd really appreciate any guidance on this. I'm working on a CLI tool that needs to handle this. For context: I'm using Python on macOS. What's the best practice here? I'm open to any suggestions. I'd really appreciate any guidance on this.