Simple countdown until a deadline.

deadline.py

import argparse
import math
import time
from datetime import datetime

from rich import box
from rich.align import Align
from rich.live import Live
from rich.panel import Panel

time_fmt = "%Y-%m-%d %H:%M:%S"


def gen(deadline: datetime) -> str:
    now = datetime.now()
    delta = (deadline - now).total_seconds()

    if deadline < now:
        return f"[bold] deadline has passed"

    h, m = divmod(delta, 3600)
    m, s = divmod(m, 60)
    h, m, s = map(math.floor, [h, m, s])

    ht = "hour" + "s" * (h > 1 or h == 0)
    mt = "minute" + "s" * (m > 1 or m == 0)
    st = "second" + "s" * (s > 1 or s == 0)

    return f"[bold]{h:2d} {ht}, {m:2d} {mt}, {s:2d} {st}"


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--deadline",
        type=lambda d: datetime.strptime(d, time_fmt),
        required=True,
        help=f"Deadline in {time_fmt.replace('%', '%%')} format.",
    )
    parser.add_argument("--refresh_per_second", type=int, default=1)
    args = parser.parse_args()

    panel = lambda: Panel(Align.center(gen(args.deadline)), expand=True, box=box.SQUARE)

    with Live(panel(), refresh_per_second=args.refresh_per_second) as live:
        while True:
            try:
                time.sleep(0.5)
                live.update(panel())
            except KeyboardInterrupt:
                break