from pathlib import Path


def get_pdb_file_suffix_variations(pdb_file_path, sep="_"):
    """
    List suffix variations of a PDB file.

    If `file.pdb` is given, and files `file_1.pdb`, `file_2.pdb`, exist
    in the folder, those will be listed.

    Parameters
    ----------
    pdb_file_path : str or Path
        The path to the source PDB file. The source PDB file does not
        need to exist and it can be just a reference name.

    sep : str
        The separation between the file base name and the suffix.
        Defaults to "_".

    Returns
    -------
    list
        List of Paths with the identified PBD files.
        If no files are found return an empty list.
    """
    basename = Path(pdb_file_path)
    abs_path = basename.resolve().parent
    return list(abs_path.glob(f"{basename.stem}{sep}*{basename.suffix}"))