langchain/document_loaders/directory.py/DirectoryLoader/load_file
class DirectoryLoader:    def load_file(
        self, item: Path, path: Path, docs: List[Document], pbar: Optional[Any]
    ) -> None:
        if item.is_file():
            if _is_visible(item.relative_to(path)) or self.load_hidden:
                try:
                    sub_docs = self.loader_cls(str(item), **self.loader_kwargs).load()
                    docs.extend(sub_docs)
                except Exception as e:
                    if self.silent_errors:
                        logger.warning(e)
                    else:
                        raise e
                finally:
                    if pbar:
                        pbar.update(1)