def get_access_pdf(pdf_dir):
    """Gets a PDF file from a directory. Fails if there are multiple PDF files

    Args:
        pdf_dir (Path obj): directory containing PDF file
    """
    pdf_files = [f for f in pdf_dir.iterdir() if f.is_file(
    ) and not f.name.startswith(".") and f.name.endswith(".pdf")]
    if len(pdf_files) == 0:
        raise Exception("No PDF file found")
    elif len(pdf_files) > 1:
        raise Exception("More than one PDF file found")
    else:
        return pdf_files[0]