run-llama/llama_index · error · ImportError

You must install the `unstructured` and `lxml` package to us

Error message

You must install the `unstructured` and `lxml` package to use this node parser.

What it means

Error "You must install the `unstructured` and `lxml` package to use this node parser." thrown in run-llama/llama_index.

Source

Thrown at llama-index-core/llama_index/core/node_parser/relational/unstructured_element.py:44

    partitioning_parameters: Optional[Dict[str, Any]] = Field(
        default={},
        description="Extra dictionary representing parameters of the partitioning process.",
    )

    def __init__(
        self,
        callback_manager: Optional[CallbackManager] = None,
        llm: Optional[Any] = None,
        summary_query_str: str = DEFAULT_SUMMARY_QUERY_STR,
        partitioning_parameters: Optional[Dict[str, Any]] = {},
    ) -> None:
        """Initialize."""
        try:
            import lxml  # noqa  # pants: no-infer-dep
            import unstructured  # noqa  # pants: no-infer-dep
        except ImportError:
            raise ImportError(
                "You must install the `unstructured` and `lxml` "
                "package to use this node parser."
            )
        callback_manager = callback_manager or CallbackManager([])

        return super().__init__(
            callback_manager=callback_manager,
            llm=llm,
            summary_query_str=summary_query_str,
            partitioning_parameters=partitioning_parameters,
        )

    @classmethod
    def class_name(cls) -> str:
        return "UnstructuredElementNodeParser"

    def get_nodes_from_node(self, node: TextNode) -> List[BaseNode]:
        """Get nodes from node."""

View on GitHub (pinned to afd0fef371)

Solutions

1. Install the required packages: `pip install unstructured lxml`.
2. Use a different node parser that does not depend on unstructured.

When it happens

Trigger: Thrown at llama-index-core/llama_index/core/node_parser/relational/unstructured_element.py:44 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of run-llama/llama_index@afd0fef371 (2026-08-15). Data as JSON: /api/errors/526a7486f12148df. Report an issue: GitHub.