huggingface: init package (#21097)

First Pr for the langchain_huggingface partner Package

- Moved some of the hugging face related class from `community` to the
new `partner package`

Still needed :
- Documentation
- Tests
- Support for the new apply_chat_template in `ChatHuggingFace`
- Confirm choice of class to support for embeddings witht he
sentence-transformer team.

cc : @efriis

---------

Co-authored-by: Cyril Kondratenko <kkn1993@gmail.com>
Co-authored-by: Erick Friis <erick@langchain.dev>

libs/partners/huggingface/langchain_huggingface/embeddings/huggingface_endpoint.py

@@ -0,0 +1,151 @@
+import json
+import os
+from typing import Any, Dict, List, Optional
+
+from langchain_core.embeddings import Embeddings
+from langchain_core.pydantic_v1 import BaseModel, Extra, root_validator
+
+DEFAULT_MODEL = "sentence-transformers/all-mpnet-base-v2"
+VALID_TASKS = ("feature-extraction",)
+
+
+class HuggingFaceEndpointEmbeddings(BaseModel, Embeddings):
+    """HuggingFaceHub embedding models.
+
+    To use, you should have the ``huggingface_hub`` python package installed, and the
+    environment variable ``HUGGINGFACEHUB_API_TOKEN`` set with your API token, or pass
+    it as a named parameter to the constructor.
+
+    Example:
+        .. code-block:: python
+
+            from langchain_community.embeddings import HuggingFaceEndpointEmbeddings
+            model = "sentence-transformers/all-mpnet-base-v2"
+            hf = HuggingFaceEndpointEmbeddings(
+                model=model,
+                task="feature-extraction",
+                huggingfacehub_api_token="my-api-key",
+            )
+    """
+
+    client: Any  #: :meta private:
+    async_client: Any  #: :meta private:
+    model: Optional[str] = None
+    """Model name to use."""
+    repo_id: Optional[str] = None
+    """Huggingfacehub repository id, for backward compatibility."""
+    task: Optional[str] = "feature-extraction"
+    """Task to call the model with."""
+    model_kwargs: Optional[dict] = None
+    """Keyword arguments to pass to the model."""
+
+    huggingfacehub_api_token: Optional[str] = None
+
+    class Config:
+        """Configuration for this pydantic object."""
+
+        extra = Extra.forbid
+
+    @root_validator()
+    def validate_environment(cls, values: Dict) -> Dict:
+        """Validate that api key and python package exists in environment."""
+        huggingfacehub_api_token = values["huggingfacehub_api_token"] or os.getenv(
+            "HUGGINGFACEHUB_API_TOKEN"
+        )
+
+        try:
+            from huggingface_hub import (  # type: ignore[import]
+                AsyncInferenceClient,
+                InferenceClient,
+            )
+
+            if values["model"]:
+                values["repo_id"] = values["model"]
+            elif values["repo_id"]:
+                values["model"] = values["repo_id"]
+            else:
+                values["model"] = DEFAULT_MODEL
+                values["repo_id"] = DEFAULT_MODEL
+
+            client = InferenceClient(
+                model=values["model"],
+                token=huggingfacehub_api_token,
+            )
+
+            async_client = AsyncInferenceClient(
+                model=values["model"],
+                token=huggingfacehub_api_token,
+            )
+
+            if values["task"] not in VALID_TASKS:
+                raise ValueError(
+                    f"Got invalid task {values['task']}, "
+                    f"currently only {VALID_TASKS} are supported"
+                )
+            values["client"] = client
+            values["async_client"] = async_client
+
+        except ImportError:
+            raise ImportError(
+                "Could not import huggingface_hub python package. "
+                "Please install it with `pip install huggingface_hub`."
+            )
+        return values
+
+    def embed_documents(self, texts: List[str]) -> List[List[float]]:
+        """Call out to HuggingFaceHub's embedding endpoint for embedding search docs.
+
+        Args:
+            texts: The list of texts to embed.
+
+        Returns:
+            List of embeddings, one for each text.
+        """
+        # replace newlines, which can negatively affect performance.
+        texts = [text.replace("\n", " ") for text in texts]
+        _model_kwargs = self.model_kwargs or {}
+        responses = self.client.post(
+            json={"inputs": texts, "parameters": _model_kwargs}, task=self.task
+        )
+        return json.loads(responses.decode())
+
+    async def aembed_documents(self, texts: List[str]) -> List[List[float]]:
+        """Async Call to HuggingFaceHub's embedding endpoint for embedding search docs.
+
+        Args:
+            texts: The list of texts to embed.
+
+        Returns:
+            List of embeddings, one for each text.
+        """
+        # replace newlines, which can negatively affect performance.
+        texts = [text.replace("\n", " ") for text in texts]
+        _model_kwargs = self.model_kwargs or {}
+        responses = await self.async_client.post(
+            json={"inputs": texts, "parameters": _model_kwargs}, task=self.task
+        )
+        return json.loads(responses.decode())
+
+    def embed_query(self, text: str) -> List[float]:
+        """Call out to HuggingFaceHub's embedding endpoint for embedding query text.
+
+        Args:
+            text: The text to embed.
+
+        Returns:
+            Embeddings for the text.
+        """
+        response = self.embed_documents([text])[0]
+        return response
+
+    async def aembed_query(self, text: str) -> List[float]:
+        """Async Call to HuggingFaceHub's embedding endpoint for embedding query text.
+
+        Args:
+            text: The text to embed.
+
+        Returns:
+            Embeddings for the text.
+        """
+        response = (await self.aembed_documents([text]))[0]
+        return response