Python class for monitoring a file in Notepad++

notepad_monitor.py

import atexit
import subprocess as subp
from pathlib import Path
from concurrent.futures import ThreadPoolExecutor


class NotepadMonitor:
    """
    A class to monitor a file in Notepad++.
    """

    __pool__ = ThreadPoolExecutor()

    def __init__(self, file: Path):
        self.__file = file
        self.__fut = None

    def __run(self):
        file = self.__file
        file.touch()
        args = [
            "notepad++",
            "-monitor",
            "-noPlugin",
            "-nosession",
            "-notabbar",
            "-ro",
            "-alwaysOnTop",
            file.as_posix(),
        ]
        subp.run(args)

    def start(self):
        if self.__fut:
            raise RuntimeError("Already started")
        self.__fut = self.__pool__.submit(self.__run)
        fp = self.__file.open("w")
        atexit.register(fp.close)
        return fp

    def wait(self):
        if self.__fut:
            self.__fut.result()
            self.__fut = None


def main():
    from time import sleep

    path_here = Path(__file__).parent
    o = NotepadMonitor(path_here / "log.txt")
    fp = o.start()
    for i in range(100):
        fp.write(f"Hello World! {i}\n")
        fp.flush()
        sleep(0.1)
    o.wait()


if __name__ == "__main__":
    main()