Python function to block execution until desired timestamp, with countdown

wait.py

from time import sleep
from datetime import datetime, timedelta


def wait(until,
         update_time=1,
         waiting_message='Waiting...',
         done_message='Done'):
    print(waiting_message)
    while (
        (countdown := until - datetime.now().replace(microsecond=0))
        .total_seconds() > 0
        ):
        print(countdown, end='\r')
        sleep(update_time)
    print(f'{countdown} {done_message}')
    
_now = datetime.now().replace(microsecond=0)
_until = _now + timedelta(seconds=20)
wait(_until)