fix exception inconsistencies (#8812) (#8839)

Merge #8812 with main to fix unrelated test failure

Co-authored-by: shibuiwilliam <shibuiyusuke@gmail.com>

libs/langchain/langchain/document_loaders/obs_directory.py

@@ -43,7 +43,7 @@ class OBSDirectoryLoader(BaseLoader):
         try:
             from obs import ObsClient
         except ImportError:
-            raise ValueError(
+            raise ImportError(
                 "Could not import esdk-obs-python python package. "
                 "Please install it with `pip install esdk-obs-python`."
             )

libs/langchain/langchain/document_loaders/obs_file.py

@@ -67,7 +67,7 @@ class OBSFileLoader(BaseLoader):
         try:
             from obs import ObsClient
         except ImportError:
-            raise ValueError(
+            raise ImportError(
                 "Could not import esdk-obs-python python package. "
                 "Please install it with `pip install esdk-obs-python`."
             )

libs/langchain/langchain/document_loaders/parsers/audio.py

@@ -149,14 +149,14 @@ class OpenAIWhisperParserLocal(BaseBlobParser):
         try:
             from pydub import AudioSegment
         except ImportError:
-            raise ValueError(
-                "pydub package not found, please install it with " "`pip install pydub`"
+            raise ImportError(
+                "pydub package not found, please install it with `pip install pydub`"
             )
 
         try:
             import librosa
         except ImportError:
-            raise ValueError(
+            raise ImportError(
                 "librosa package not found, please install it with "
                 "`pip install librosa`"
             )

libs/langchain/langchain/document_loaders/parsers/pdf.py

@@ -183,7 +183,7 @@ class AmazonTextractPDFParser(BaseBlobParser):
             else:
                 self.textract_features = []
         except ImportError:
-            raise ModuleNotFoundError(
+            raise ImportError(
                 "Could not import amazon-textract-caller python package. "
                 "Please install it with `pip install amazon-textract-caller`."
             )
@@ -194,7 +194,7 @@ class AmazonTextractPDFParser(BaseBlobParser):
 
                 self.boto3_textract_client = boto3.client("textract")
             except ImportError:
-                raise ModuleNotFoundError(
+                raise ImportError(
                     "Could not import boto3 python package. "
                     "Please install it with `pip install boto3`."
                 )

libs/langchain/langchain/embeddings/openai.py

@@ -295,7 +295,13 @@ class OpenAIEmbeddings(BaseModel, Embeddings):
         if self.openai_api_type in ("azure", "azure_ad", "azuread"):
             openai_args["engine"] = self.deployment
         if self.openai_proxy:
-            import openai
+            try:
+                import openai
+            except ImportError:
+                raise ImportError(
+                    "Could not import openai python package. "
+                    "Please install it with `pip install openai`."
+                )
 
             openai.proxy = {
                 "http": self.openai_proxy,

libs/langchain/langchain/evaluation/string_distance/base.py

@@ -30,6 +30,7 @@ def _load_rapidfuzz() -> Any:
     except ImportError:
         raise ImportError(
             "Please install the rapidfuzz library to use the FuzzyMatchStringEvaluator."
+            "Please install it with `pip install rapidfuzz`."
         )
     return rapidfuzz.distance
 

libs/langchain/langchain/memory/chat_message_histories/cosmos_db.py

@@ -66,6 +66,7 @@ class CosmosDBChatMessageHistory(BaseChatMessageHistory):
         except ImportError as exc:
             raise ImportError(
                 "You must install the azure-cosmos package to use the CosmosDBChatMessageHistory."  # noqa: E501
+                "Please install it with `pip install azure-cosmos`."
             ) from exc
         if self.credential:
             self._client = CosmosClient(
@@ -94,6 +95,7 @@ class CosmosDBChatMessageHistory(BaseChatMessageHistory):
         except ImportError as exc:
             raise ImportError(
                 "You must install the azure-cosmos package to use the CosmosDBChatMessageHistory."  # noqa: E501
+                "Please install it with `pip install azure-cosmos`."
             ) from exc
         database = self._client.create_database_if_not_exists(self.cosmos_database)
         self._container = database.create_container_if_not_exists(
@@ -130,6 +132,7 @@ class CosmosDBChatMessageHistory(BaseChatMessageHistory):
         except ImportError as exc:
             raise ImportError(
                 "You must install the azure-cosmos package to use the CosmosDBChatMessageHistory."  # noqa: E501
+                "Please install it with `pip install azure-cosmos`."
             ) from exc
         try:
             item = self._container.read_item(

libs/langchain/langchain/prompts/example_selector/ngram_overlap.py

@@ -72,8 +72,9 @@ class NGramOverlapExampleSelector(BaseExampleSelector, BaseModel):
                 sentence_bleu,
             )
         except ImportError as e:
-            raise ValueError(
-                "Not all the correct dependencies for this ExampleSelect exist"
+            raise ImportError(
+                "Not all the correct dependencies for this ExampleSelect exist."
+                "Please install nltk with `pip install nltk`."
             ) from e
 
         return values