How to convert a time aware string to its respective UTC format in Python?

Question

All the links I saw were about converting local time to UTC.

But, I have a time aware string 2023-01-24T22:18:00.089-05:00. How do I convert it to its respective UTC format 2023-01-25T03:18:00.089Z in python?

Answer 1

Convert the string to a datetime object (make sure to correctly parse the UTC offset), convert to UTC, then format back to string. For example like

from datetime import datetime, timezone

print(
      datetime.fromisoformat("2023-01-24T22:18:00.089-05:00") # parse
      .astimezone(timezone.utc) # to UTC
      .isoformat(timespec="milliseconds") # back to ISO 8601 string
      .replace("+00:00", "Z") # UTC as Z
)

# 2023-01-25T03:18:00.089Z

Note that fromisoformat is a Python 3.7 feature and that there is currently way to directly represent UTC as 'Z' (zulu), so I'm using .replace("+00:00", "Z").