Add langchain as optional dependency.

Author: qiuosier

ads/llm/__init__.py

@@ -4,8 +4,15 @@
 # Copyright (c) 2023 Oracle and/or its affiliates.
 # Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
 
-
-from ads.llm.langchain.plugins.llm_gen_ai import GenerativeAI
-from ads.llm.langchain.plugins.llm_md import ModelDeploymentTGI
-from ads.llm.langchain.plugins.llm_md import ModelDeploymentVLLM
-from ads.llm.langchain.plugins.embeddings import GenerativeAIEmbeddings
+try:
+    import langchain
+    from ads.llm.langchain.plugins.llm_gen_ai import GenerativeAI
+    from ads.llm.langchain.plugins.llm_md import ModelDeploymentTGI
+    from ads.llm.langchain.plugins.llm_md import ModelDeploymentVLLM
+    from ads.llm.langchain.plugins.embeddings import GenerativeAIEmbeddings
+except ImportError as ex:
+    if ex.name == "langchain":
+        raise ImportError(
+            f"{ex.msg}\nPlease install/update langchain with `pip install langchain -U`"
+        ) from ex
+    raise ex

dev-requirements.txt

@@ -1,5 +1,5 @@
 -r test-requirements.txt
--e ".[bds,data,geo,huggingface,notebook,onnx,opctl,optuna,pii,spark,tensorflow,text,torch,viz]"
+-e ".[bds,data,geo,huggingface,llm,notebook,onnx,opctl,optuna,pii,spark,tensorflow,text,torch,viz]"
 arff
 category_encoders
 dask

pyproject.toml

@@ -181,6 +181,9 @@ pii = [
   "spacy-transformers==1.2.5",
   "spacy==3.6.1",
 ]
+llm = [
+  "langchain>=0.0.295"
+]
 
 [project.urls]
 "Github" = "https://github.com/oracle/accelerated-data-science"