python - convert datetime to UTC time

Question

I would like to convert datetime to UTC time. I try below code but the output looks like not correct:

import datetime
import pandas as pd

def str2dt(tstr):
    dt = datetime.datetime.strptime(tstr, '%m-%d %H:%M:%S.%f')
    return dt

ts = "04-12 20:43:34.342"
dt = str2dt(ts)

utc_delta = datetime.datetime.utcnow() - datetime.datetime.now()
utc = dt - utc_delta
print(dt,'->',utc)

Current output: 1900-04-12 20:43:34.342000 -> 1900-04-12 15:43:34.342001

The expected output time is 1900-04-12 02:43:34.342001

Answer 1

It looks like you would be better off using isoformat() on your datetime:

utc = dt.isoformat(sep=' ')  # The normal date-time separator is 'T', but that isn't very readable
print(f"{dt} -> {utc}")

This gives you the answer you're looking for.

If you still need the UTC offset, consider using datetime.datetime.utcoffset().

Answer 2

Should be plus the delta:

import datetime
import pandas as pd

def str2dt(tstr):
    dt = datetime.datetime.strptime(tstr, '%m-%d %H:%M:%S.%f')
    return dt

ts = "04-12 20:43:34.342"
dt = str2dt(ts)

utc_delta = datetime.datetime.utcnow() - datetime.datetime.now()
utc = dt + utc_delta
print(dt,'->',utc)

Output:

1900-04-12 20:43:34.342000 -> 1900-04-13 01:43:34.341999