filePipeline

class PdfFilesPipeline(FilesPipeline):
    def get_media_requests(self, item, info):
        urls = ItemAdapter(item).get(self.files_urls_field, [])
        # file_name defined here
        return [Request(u, meta={'filename': item.get('file_name')}) for u in urls]

    def file_path(self, request, response=None, info=None):
        return 'full/%s%s' % (urllib.parse.unquote(request.meta['filename'], encoding='utf-8', errors='replace'), '.pdf')