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Kendra

亚马逊Kendra检索器 #

基类:EventBaseRetriever

AWS Kendra检索器,适用于LlamaIndex。

更多信息请参见 https://aws.amazon.com/kendra/。

参数:

名称 类型 描述 默认
index_id str

Kendra 索引 ID。

required
query_config Optional[Dict[str, Any]]

用于查询Kendra的配置。

None
profile_name Optional[str]

在 ~/.aws/credentials 或 ~/.aws/config 文件中配置文件的名称,该文件包含访问密钥或角色信息。如果未指定,将使用默认凭据配置文件,如果在 EC2 实例上,则使用来自 IMDS 的凭据。

None
region_name Optional[str]

AWS 区域,例如 us-west-2。 回退到 AWS_DEFAULT_REGION 环境变量或在 ~/.aws/config 中指定的区域。

None
aws_access_key_id Optional[str]

aws访问密钥ID。

None
aws_secret_access_key Optional[str]

aws 密钥访问密钥。

None
aws_session_token Optional[str]

AWS临时会话令牌。

None
示例

.. 代码块:: python

from llama_index.retrievers.kendra import AmazonKendraRetriever

retriever = AmazonKendraRetriever(
    index_id="<kendra-index-id>",
    query_config={
        "PageSize": 4,
        "AttributeFilter": {
            "EqualsTo": {
                "Key": "tag",
                "Value": {"StringValue": "space"}
            }
        }
    },
)
workflows/handler.py 中的源代码llama_index/retrievers/kendra/base.py
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class AmazonKendraRetriever(BaseRetriever):
    """
    AWS Kendra retriever for LlamaIndex.

    See https://aws.amazon.com/kendra/ for more info.

    Args:
        index_id: Kendra Index ID.
        query_config: Configuration for querying Kendra.
        profile_name: The name of the profile in the ~/.aws/credentials
            or ~/.aws/config files, which has either access keys or role information
            specified. If not specified, the default credential profile or, if on an
            EC2 instance, credentials from IMDS will be used.
        region_name: The aws region e.g., `us-west-2`.
            Fallback to AWS_DEFAULT_REGION env variable or region specified in
            ~/.aws/config.
        aws_access_key_id: The aws access key id.
        aws_secret_access_key: The aws secret access key.
        aws_session_token: AWS temporary session token.

    Example:
        .. code-block:: python

            from llama_index.retrievers.kendra import AmazonKendraRetriever

            retriever = AmazonKendraRetriever(
                index_id="<kendra-index-id>",
                query_config={
                    "PageSize": 4,
                    "AttributeFilter": {
                        "EqualsTo": {
                            "Key": "tag",
                            "Value": {"StringValue": "space"}
                        }
                    }
                },
            )

    """

    # Mapping of Kendra confidence levels to float scores
    CONFIDENCE_SCORES = {
        "VERY_HIGH": 1.0,
        "HIGH": 0.8,
        "MEDIUM": 0.6,
        "LOW": 0.4,
        "NOT_AVAILABLE": 0.0,
    }

    def __init__(
        self,
        index_id: str,
        query_config: Optional[Dict[str, Any]] = None,
        profile_name: Optional[str] = None,
        region_name: Optional[str] = None,
        aws_access_key_id: Optional[str] = None,
        aws_secret_access_key: Optional[str] = None,
        aws_session_token: Optional[str] = None,
        callback_manager: Optional[CallbackManager] = None,
    ):
        self._client = get_aws_service_client(
            service_name="kendra",
            profile_name=profile_name,
            region_name=region_name,
            aws_access_key_id=aws_access_key_id,
            aws_secret_access_key=aws_secret_access_key,
            aws_session_token=aws_session_token,
        )
        # Create async session with the same credentials
        self._async_session = aioboto3.Session(
            profile_name=profile_name,
            region_name=region_name,
            aws_access_key_id=aws_access_key_id,
            aws_secret_access_key=aws_secret_access_key,
            aws_session_token=aws_session_token,
        )
        self.index_id = index_id
        self.query_config = query_config or {}
        super().__init__(callback_manager)

    def _parse_response(self, response: Dict[str, Any]) -> List[NodeWithScore]:
        """Parse Kendra response into NodeWithScore objects."""
        node_with_score = []
        result_items = response.get("ResultItems", [])

        for result in result_items:
            text = ""
            metadata = {}

            # Extract text based on result type
            if result.get("Type") == "ANSWER":
                text = (
                    result.get("AdditionalAttributes", [{}])[0]
                    .get("Value", {})
                    .get("TextWithHighlightsValue", {})
                    .get("Text", "")
                )
            elif result.get("Type") == "DOCUMENT":
                text = result.get("DocumentExcerpt", {}).get("Text", "")

            # Extract metadata
            if "DocumentId" in result:
                metadata["document_id"] = result["DocumentId"]
            if "DocumentTitle" in result:
                metadata["title"] = result.get("DocumentTitle", {}).get("Text", "")
            if "DocumentURI" in result:
                metadata["source"] = result["DocumentURI"]

            # Only create nodes for results with actual content
            if text:
                # Convert Kendra's confidence score to float
                confidence = result.get("ScoreAttributes", {}).get(
                    "ScoreConfidence", "NOT_AVAILABLE"
                )
                score = self.CONFIDENCE_SCORES.get(confidence, 0.0)

                node_with_score.append(
                    NodeWithScore(
                        node=TextNode(
                            text=text,
                            metadata=metadata,
                        ),
                        score=score,
                    )
                )

        return node_with_score

    def _retrieve(self, query_bundle: QueryBundle) -> List[NodeWithScore]:
        """Synchronous retrieve method."""
        query = query_bundle.query_str

        query_params = {
            "IndexId": self.index_id,
            "QueryText": query.strip(),
            **self.query_config,
        }

        response = self._client.query(**query_params)
        return self._parse_response(response)

    async def _aretrieve(self, query_bundle: QueryBundle) -> List[NodeWithScore]:
        """Asynchronous retrieve method."""
        query = query_bundle.query_str

        query_params = {
            "IndexId": self.index_id,
            "QueryText": query.strip(),
            **self.query_config,
        }

        async with self._async_session.client("kendra") as client:
            response = await client.query(**query_params)
            return self._parse_response(response)

选项: 成员:- AmazonKendraRetriever