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Markdown

节点解析器。

MarkdownNodeParser #

Bases: NodeParser

Markdown节点解析器。

使用自定义的Markdown拆分逻辑将文档拆分为节点。

Source code in llama_index/core/node_parser/file/markdown.py
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class MarkdownNodeParser(NodeParser):
    """Markdown节点解析器。

使用自定义的Markdown拆分逻辑将文档拆分为节点。

Args:
    include_metadata(布尔值):是否在节点中包含元数据
    include_prev_next_rel(布尔值):是否包含上一个/下一个关系"""

    @classmethod
    def from_defaults(
        cls,
        include_metadata: bool = True,
        include_prev_next_rel: bool = True,
        callback_manager: Optional[CallbackManager] = None,
    ) -> "MarkdownNodeParser":
        callback_manager = callback_manager or CallbackManager([])

        return cls(
            include_metadata=include_metadata,
            include_prev_next_rel=include_prev_next_rel,
            callback_manager=callback_manager,
        )

    @classmethod
    def class_name(cls) -> str:
        """获取类名。"""
        return "MarkdownNodeParser"

    def _parse_nodes(
        self,
        nodes: Sequence[BaseNode],
        show_progress: bool = False,
        **kwargs: Any,
    ) -> List[BaseNode]:
        all_nodes: List[BaseNode] = []
        nodes_with_progress = get_tqdm_iterable(nodes, show_progress, "Parsing nodes")

        for node in nodes_with_progress:
            nodes = self.get_nodes_from_node(node)
            all_nodes.extend(nodes)

        return all_nodes

    def get_nodes_from_node(self, node: BaseNode) -> List[TextNode]:
        """从文档中获取节点。"""
        text = node.get_content(metadata_mode=MetadataMode.NONE)
        markdown_nodes = []
        lines = text.split("\n")
        metadata: Dict[str, str] = {}
        code_block = False
        current_section = ""

        for line in lines:
            if line.lstrip().startswith("```"):
                code_block = not code_block
            header_match = re.match(r"^(#+)\s(.*)", line)
            if header_match and not code_block:
                if current_section != "":
                    markdown_nodes.append(
                        self._build_node_from_split(
                            current_section.strip(), node, metadata
                        )
                    )
                metadata = self._update_metadata(
                    metadata, header_match.group(2), len(header_match.group(1).strip())
                )
                current_section = f"{header_match.group(2)}\n"
            else:
                current_section += line + "\n"

        markdown_nodes.append(
            self._build_node_from_split(current_section.strip(), node, metadata)
        )

        return markdown_nodes

    def _update_metadata(
        self, headers_metadata: dict, new_header: str, new_header_level: int
    ) -> dict:
        """更新元数据的Markdown标题。

删除所有等于或小于新发现标题级别的标题。
"""
        updated_headers = {}

        for i in range(1, new_header_level):
            key = f"Header_{i}"
            if key in headers_metadata:
                updated_headers[key] = headers_metadata[key]

        updated_headers[f"Header_{new_header_level}"] = new_header
        return updated_headers

    def _build_node_from_split(
        self,
        text_split: str,
        node: BaseNode,
        metadata: dict,
    ) -> TextNode:
        """从单个文本拆分构建节点。"""
        node = build_nodes_from_splits([text_split], node, id_func=self.id_func)[0]

        if self.include_metadata:
            node.metadata = {**node.metadata, **metadata}

        return node

class_name classmethod #

class_name() -> str

获取类名。

Source code in llama_index/core/node_parser/file/markdown.py
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@classmethod
def class_name(cls) -> str:
    """获取类名。"""
    return "MarkdownNodeParser"

get_nodes_from_node #

get_nodes_from_node(node: BaseNode) -> List[TextNode]

从文档中获取节点。

Source code in llama_index/core/node_parser/file/markdown.py
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def get_nodes_from_node(self, node: BaseNode) -> List[TextNode]:
    """从文档中获取节点。"""
    text = node.get_content(metadata_mode=MetadataMode.NONE)
    markdown_nodes = []
    lines = text.split("\n")
    metadata: Dict[str, str] = {}
    code_block = False
    current_section = ""

    for line in lines:
        if line.lstrip().startswith("```"):
            code_block = not code_block
        header_match = re.match(r"^(#+)\s(.*)", line)
        if header_match and not code_block:
            if current_section != "":
                markdown_nodes.append(
                    self._build_node_from_split(
                        current_section.strip(), node, metadata
                    )
                )
            metadata = self._update_metadata(
                metadata, header_match.group(2), len(header_match.group(1).strip())
            )
            current_section = f"{header_match.group(2)}\n"
        else:
            current_section += line + "\n"

    markdown_nodes.append(
        self._build_node_from_split(current_section.strip(), node, metadata)
    )

    return markdown_nodes