def getInodeNumber(self):
        """
        Retrieve the file serial number, also called inode number, which
        distinguishes this file from all other files on the same device.

        @raise NotImplementedError: if the platform is Windows, since the
            inode number would be a dummy value for all files in Windows
        @return: a number representing the file serial number
        @rtype: L{int}
        @since: 11.0
        """
        if platform.isWindows():
            raise NotImplementedError

        st = self._statinfo
        if not st:
            self.restat()
            st = self._statinfo
        return st.st_ino

        Retrieve the file serial number, also called inode number, which
        distinguishes this file from all other files on the same device.

        @raise NotImplementedError: if the platform is Windows, since the
            inode number would be a dummy value for all files in Windows
        @return: a number representing the file serial number
        @rtype: L{int}
        @since: 11.0
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/filepath.py