Python: Figure out local timezone

Question

I want to compare UTC timestamps from a log file with local timestamps. When creating the local datetime object, I use something like:

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Answer 1

I want to compare UTC timestamps from a log file with local timestamps

If this is your intent, then I wouldn't worry about specifying specific tzinfo parameters or any additional external libraries. Since Python 3.5, the built in datetime module is all you need to create a UTC and a local timestamp automatically.

import datetime
f = "%a %b %d %H:%M:%S %Z %Y"         # Full format with timezone

# tzinfo=None
cdatetime = datetime.datetime(2010, 4, 27, 12, 0, 0, 0)  # 1. Your example from log
cdatetime = datetime.datetime.now()   # 2. Basic date creation (default: local time)
print(cdatetime.strftime(f))          # no timezone printed
# Tue Apr 27 12:00:00  2010

utctimestamp = cdatetime.astimezone(tz=datetime.timezone.utc)  # 1. convert to UTC
utctimestamp = datetime.datetime.now(tz=datetime.timezone.utc) # 2. create in UTC
print(utctimestamp.strftime(f))
# Tue Apr 27 17:00:00 UTC 2010

localtimestamp = cdatetime.astimezone()               # 1. convert to local [default]
localtimestamp = datetime.datetime.now().astimezone()  # 2. create with local timezone
print(localtimestamp.strftime(f))
# Tue Apr 27 12:00:00 CDT 2010

The '%Z' parameter of datetime.strftime() prints the timezone acronym into the timestamp for humans to read.