Use of Deprecated `utcnow()` or `utcfromtimestamp()` APIs

[ShreyTiwari]

Hi there! 👋

I noticed that the codebase uses datetime.utcnow() or datetime.utcfromtimestamp(). These are deprecated and won't work with Python 3.12. They also handle naïve datetimes, which can lead to bugs. Could we switch to timezone-aware alternatives?

CodeQL Alerts

Here are the specific instances CodeQL flagged:

1. Location: https://github.com/GoogleCloudPlatform/cortex-data-foundation/blob/33d4c978101ecd90d83f45aab3f6f9a19a916288/src/k9/src/catgap/catgap_pipeline/pipeline_job/matches_writer.py#L97

Explanation

Issue:

• datetime.utcnow() and datetime.utcfromtimestamp() return naïve datetimes (without timezone info).
• In Python 3, naïve datetimes are interpreted as system-local times, causing inconsistencies.
• These methods are deprecated and no longer work in Python 3.12.

Example Problem:

from datetime import datetime
ts = 1571595618.0
x = datetime.utcfromtimestamp(ts)
x_ts = x.timestamp()
assert ts == x_ts, f"{ts} != {x_ts}" # Can fail in non-UTC locales

Recommended Solution: Switch to time zone-aware methods:

from datetime import datetime, timezone
# Replace utcnow()
dt_now = datetime.now(tz=timezone.utc)
# Replace utcfromtimestamp()
ts = 1571595618.0
x = datetime.fromtimestamp(ts, tz=timezone.utc)
x_ts = x.timestamp()
assert ts == x_ts, f"{ts} != {x_ts}" # This succeeds

Action Required:

• Replace all instances of datetime.utcnow() with datetime.now(tz=timezone.utc).
• Replace all instances of datetime.utcfromtimestamp() with datetime.fromtimestamp(ts, tz=timezone.utc).

References:

For more details, see:

• Stop using utcnow and utcfromtimestamp
• Python Documentation

Thank you so much for your time and effort in maintaining this project! 🌟

Best, Shrey

[TXZebra]

Thank you for your input, we very much appreciate it. We will be looking at this for a future roadmap item.