community[patch]: Update root_validators embeddings: llamacpp, jina, dashscope, mosaicml, huggingface_hub, Toolkits: Connery, ChatModels: PAI_EAS, (#22828)

This PR updates root validators for:

* Embeddings: llamacpp, jina, dashscope, mosaicml, huggingface_hub
* Toolkits: Connery
* ChatModels: PAI_EAS

Following this issue:
https://github.com/langchain-ai/langchain/issues/22819

libs/community/langchain_community/agent_toolkits/connery/toolkit.py

@@ -19,7 +19,7 @@ class ConneryToolkit(BaseToolkit):
         """
         return self.tools
 
-    @root_validator()
+    @root_validator(pre=True)
     def validate_attributes(cls, values: dict) -> dict:
         """
         Validate the attributes of the ConneryToolkit class.

libs/community/langchain_community/chat_models/pai_eas_endpoint.py

@@ -67,7 +67,7 @@ class PaiEasChatEndpoint(BaseChatModel):
 
     timeout: Optional[int] = 5000
 
-    @root_validator()
+    @root_validator(pre=True)
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate that api key and python package exists in environment."""
         values["eas_service_url"] = get_from_dict_or_env(

libs/community/langchain_community/embeddings/dashscope.py

@@ -110,7 +110,7 @@ class DashScopeEmbeddings(BaseModel, Embeddings):
 
         extra = Extra.forbid
 
-    @root_validator()
+    @root_validator(pre=True)
     def validate_environment(cls, values: Dict) -> Dict:
         import dashscope
 

libs/community/langchain_community/embeddings/huggingface_hub.py

@@ -1,10 +1,10 @@
 import json
-import os
 from typing import Any, Dict, List, Optional
 
 from langchain_core._api import deprecated
 from langchain_core.embeddings import Embeddings
 from langchain_core.pydantic_v1 import BaseModel, Extra, root_validator
+from langchain_core.utils import get_from_dict_or_env
 
 DEFAULT_MODEL = "sentence-transformers/all-mpnet-base-v2"
 VALID_TASKS = ("feature-extraction",)
@@ -52,19 +52,19 @@ class HuggingFaceHubEmbeddings(BaseModel, Embeddings):
 
         extra = Extra.forbid
 
-    @root_validator()
+    @root_validator(pre=True)
     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"
+        huggingfacehub_api_token = get_from_dict_or_env(
+            values, "huggingfacehub_api_token", "HUGGINGFACEHUB_API_TOKEN"
         )
 
         try:
             from huggingface_hub import AsyncInferenceClient, InferenceClient
 
-            if values["model"]:
+            if values.get("model"):
                 values["repo_id"] = values["model"]
-            elif values["repo_id"]:
+            elif values.get("repo_id"):
                 values["model"] = values["repo_id"]
             else:
                 values["model"] = DEFAULT_MODEL
@@ -80,11 +80,6 @@ class HuggingFaceHubEmbeddings(BaseModel, Embeddings):
                 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
 
@@ -95,6 +90,16 @@ class HuggingFaceHubEmbeddings(BaseModel, Embeddings):
             )
         return values
 
+    @root_validator(pre=False, skip_on_failure=True)
+    def post_init(cls, values: Dict) -> Dict:
+        """Post init validation for the class."""
+        if values["task"] not in VALID_TASKS:
+            raise ValueError(
+                f"Got invalid task {values['task']}, "
+                f"currently only {VALID_TASKS} are supported"
+            )
+        return values
+
     def embed_documents(self, texts: List[str]) -> List[List[float]]:
         """Call out to HuggingFaceHub's embedding endpoint for embedding search docs.
 

libs/community/langchain_community/embeddings/jina.py

@@ -30,7 +30,7 @@ class JinaEmbeddings(BaseModel, Embeddings):
     model_name: str = "jina-embeddings-v2-base-en"
     jina_api_key: Optional[SecretStr] = None
 
-    @root_validator()
+    @root_validator(pre=True)
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate that auth token exists in environment."""
         try:

libs/community/langchain_community/embeddings/llamacpp.py

@@ -62,7 +62,7 @@ class LlamaCppEmbeddings(BaseModel, Embeddings):
 
         extra = Extra.forbid
 
-    @root_validator()
+    @root_validator(pre=False, skip_on_failure=True)
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate that llama-cpp-python library is installed."""
         model_path = values["model_path"]

libs/community/langchain_community/embeddings/mosaicml.py

@@ -46,7 +46,7 @@ class MosaicMLInstructorEmbeddings(BaseModel, Embeddings):
 
         extra = Extra.forbid
 
-    @root_validator()
+    @root_validator(pre=True)
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate that api key and python package exists in environment."""
         mosaicml_api_token = get_from_dict_or_env(