Atomic file write with temp file and rename

import os
import tempfile
from pathlib import Path


def atomic_write(path: str | Path, text: str) -> None:
    """Replace a file atomically: write a temp file, sync it, then rename."""
    target = Path(path)
    target.parent.mkdir(parents=True, exist_ok=True)
    fd, tmp_name = tempfile.mkstemp(dir=target.parent, prefix=f".{target.name}.")
    try:
        with os.fdopen(fd, "w", encoding="utf-8", newline="\n") as handle:
            handle.write(text)
            handle.flush()
            os.fsync(handle.fileno())
        os.replace(tmp_name, target)
    except BaseException:
        try:
            os.unlink(tmp_name)
        except FileNotFoundError:
            pass
        raise


if __name__ == "__main__":
    atomic_write("build/report.txt", "all good\n")