It uses a temporary file in the same directory as the given path. This ensures
that the temporary file resides on the same filesystem.

The temporary file will then be atomically moved to the target location: On
POSIX, it will use rename if files should be overwritten, otherwise a
combination of link and unlink. On Windows, it uses MoveFileEx through
stdlib’s ctypes with the appropriate flags.

Note that with link and unlink, there’s a timewindow where the file might be
available under two entries in the filesystem: The name of the temporary file,
and the name of the target file.

Also note that the permissions of the target file may change this way. In some
situations a chmod can be issued without any concurrency problems, but since
that is not always the case, this library doesn’t do it by itself.

Optional dependency: python3