Sorting a List of Dates in Python - implementing Timezone-Aware Datetime Objects
Could someone explain I've tried everything I can think of but I'm trying to configure I'm working on a personal project and I'm trying to sort a list of timezone-aware datetime objects in Python, but I'm running into unexpected behavior. I have a list of dates that include timezones, and when I sort them using the built-in `sorted()` function, the order is not what I expect. Here’s the code I’m working with: ```python from datetime import datetime, timezone, timedelta # Sample data with different timezones dates = [ datetime(2023, 10, 1, 12, 0, tzinfo=timezone.utc), datetime(2023, 10, 1, 14, 0, tzinfo=timezone(timedelta(hours=2))), datetime(2023, 10, 1, 10, 0, tzinfo=timezone(timedelta(hours=-5))), ] # Attempting to sort the list sorted_dates = sorted(dates) print(sorted_dates) ``` When I run this code, I expect the list to be sorted in chronological order. However, the output I get seems incorrect: ``` [datetime.datetime(2023, 10, 1, 12, 0, tzinfo=datetime.timezone.utc), datetime.datetime(2023, 10, 1, 14, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))), datetime.datetime(2023, 10, 1, 10, 0, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=68400)))] ``` The datetime object with the UTC timezone is coming first, but I thought that the UTC time should be equivalent to earlier local times when adjusting for timezones. I've also tried using a custom key function to normalize the datetimes to UTC for comparison: ```python sorted_dates = sorted(dates, key=lambda dt: dt.astimezone(timezone.utc)) ``` But that still doesn't yield the expected results. I'm using Python 3.9, and I want to ensure that the list is sorted accurately regardless of the timezone of the datetime objects. What am I doing wrong, or is there a better approach to achieve this? I'm working on a web app that needs to handle this. What's the best practice here? I'm using Python 3.10 in this project. Any advice would be much appreciated. What's the correct way to implement this? Thanks for taking the time to read this!