community: Add deprecation notice for Databricks integration in langchain-community (#27355)

We have released the
[langchain-databricks](https://github.com/langchain-ai/langchain-databricks)
package for Databricks integration. This PR deprecates the legacy
classes within `langchain-community`.

---------

Signed-off-by: B-Step62 <yuki.watanabe@databricks.com>
Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/langchain_community/chat_models/databricks.py

@@ -1,11 +1,18 @@
 import logging
 from urllib.parse import urlparse
 
+from langchain_core._api import deprecated
+
 from langchain_community.chat_models.mlflow import ChatMlflow
 
 logger = logging.getLogger(__name__)
 
 
+@deprecated(
+    since="0.3.3",
+    removal="1.0",
+    alternative_import="langchain_databricks.ChatDatabricks",
+)
 class ChatDatabricks(ChatMlflow):
     """`Databricks` chat models API.
 

libs/community/langchain_community/embeddings/databricks.py

@@ -3,6 +3,8 @@ from __future__ import annotations
 from typing import Iterator, List
 from urllib.parse import urlparse
 
+from langchain_core._api import deprecated
+
 from langchain_community.embeddings.mlflow import MlflowEmbeddings
 
 
@@ -11,6 +13,11 @@ def _chunk(texts: List[str], size: int) -> Iterator[List[str]]:
         yield texts[i : i + size]
 
 
+@deprecated(
+    since="0.3.3",
+    removal="1.0",
+    alternative_import="langchain_databricks.DatabricksEmbeddings",
+)
 class DatabricksEmbeddings(MlflowEmbeddings):
     """Databricks embeddings.
 

libs/community/langchain_community/llms/databricks.py

@@ -5,6 +5,7 @@ from abc import ABC, abstractmethod
 from typing import Any, Callable, Dict, List, Mapping, Optional
 
 import requests
+from langchain_core._api import deprecated
 from langchain_core.callbacks import CallbackManagerForLLMRun
 from langchain_core.language_models import LLM
 from pydantic import (
@@ -262,6 +263,11 @@ def _pickle_fn_to_hex_string(fn: Callable) -> str:
         raise ValueError(f"Failed to pickle the function: {e}")
 
 
+@deprecated(
+    since="0.3.3",
+    removal="1.0",
+    alternative_import="langchain_databricks.ChatDatabricks",
+)
 class Databricks(LLM):
     """Databricks serving endpoint or a cluster driver proxy app for LLM.
 

libs/community/langchain_community/vectorstores/databricks_vector_search.py

@@ -16,7 +16,7 @@ from typing import (
 )
 
 import numpy as np
-from langchain_core._api import warn_deprecated
+from langchain_core._api import deprecated, warn_deprecated
 from langchain_core.documents import Document
 from langchain_core.embeddings import Embeddings
 from langchain_core.vectorstores import VST, VectorStore
@@ -29,6 +29,11 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
+@deprecated(
+    since="0.3.3",
+    removal="1.0",
+    alternative_import="langchain_databricks.DatabricksVectorSearch",
+)
 class DatabricksVectorSearch(VectorStore):
     """`Databricks Vector Search` vector store.