Bob向けの効果的なプロンプトを書く

from datetime import datetime

def print_datetime():
    now = datetime.now()
    print(now.strftime("%Y-%m-%d %H:%M:%S"))

"""
utc_datetime.py — Utility for printing the current UTC date and time.
"""

from datetime import datetime, timezone

def print_utc_datetime() -> None:
    """Print the current date and time in UTC (ISO 8601 format).

    Retrieves the current moment from the system clock, attaches UTC timezone
    info, formats it as an ISO 8601 string, and writes it to stdout.

    Returns:
        None

    Raises:
        OSError: If the system clock cannot be read (e.g., hardware failure or
            OS-level permission restrictions).
        ValueError: If datetime formatting unexpectedly fails (e.g., year out
            of the supported range).

    Example:
        >>> print_utc_datetime()
        Current UTC date and time: 2025-07-15T13:42:00.123456+00:00
    """
    try:
        now_utc: datetime = datetime.now(tz=timezone.utc)
    except OSError as exc:
        # System clock is unavailable or inaccessible.
        raise OSError("Failed to read the system clock.") from exc

    try:
        formatted: str = now_utc.isoformat()
    except ValueError as exc:
        # Extremely unlikely, but guard against out-of-range datetime values.
        raise ValueError(
            f"Failed to format the datetime object: {now_utc!r}"
        ) from exc

    print(f"Current UTC date and time: {formatted}")


if __name__ == "__main__":
    print_utc_datetime()