Files
pr-agent/pr_agent/algo/ai_handlers/langchain_ai_handler.py
Akileo d791e9f3d1 Fix: Improve langchain import error handling and add img_path to handler
Addresses issue #1784:
- Raises ImportError if langchain is not installed when LangChainOpenAIHandler is initialized.
- Adds img_path parameter to LangChainOpenAIHandler.chat_completion for interface consistency.
- Logs a warning if img_path is used with LangChainOpenAIHandler.
2025-05-25 15:28:18 +09:00

93 lines
3.9 KiB
Python

_LANGCHAIN_INSTALLED = False
try:
from langchain_core.messages import HumanMessage, SystemMessage
from langchain_openai import AzureChatOpenAI, ChatOpenAI
_LANGCHAIN_INSTALLED = True
except: # we don't enforce langchain as a dependency, so if it's not installed, just move on
pass
import functools
from typing import Optional
import openai
from tenacity import retry, retry_if_exception_type, retry_if_not_exception_type, stop_after_attempt
from pr_agent.algo.ai_handlers.base_ai_handler import BaseAiHandler
from pr_agent.config_loader import get_settings
from pr_agent.log import get_logger
OPENAI_RETRIES = 5
class LangChainOpenAIHandler(BaseAiHandler):
def __init__(self):
if not _LANGCHAIN_INSTALLED:
raise ImportError("LangChain is not installed. Please install it with `pip install langchain`.")
super().__init__()
self.azure = get_settings().get("OPENAI.API_TYPE", "").lower() == "azure"
# Create a default unused chat object to trigger early validation
self._create_chat(self.deployment_id)
def chat(self, messages: list, model: str, temperature: float):
chat = self._create_chat(self.deployment_id)
return chat.invoke(input=messages, model=model, temperature=temperature)
@property
def deployment_id(self):
"""
Returns the deployment ID for the OpenAI API.
"""
return get_settings().get("OPENAI.DEPLOYMENT_ID", None)
@retry(
retry=retry_if_exception_type(openai.APIError) & retry_if_not_exception_type(openai.RateLimitError),
stop=stop_after_attempt(OPENAI_RETRIES),
)
async def chat_completion(self, model: str, system: str, user: str, temperature: float = 0.2, img_path: Optional[str] = None):
if img_path:
get_logger().warning(f"Image path is not supported for LangChainOpenAIHandler. Ignoring image path: {img_path}")
try:
messages = [SystemMessage(content=system), HumanMessage(content=user)]
# get a chat completion from the formatted messages
resp = self.chat(messages, model=model, temperature=temperature)
finish_reason = "completed"
return resp.content, finish_reason
except openai.RateLimitError as e:
get_logger().error(f"Rate limit error during LLM inference: {e}")
raise
except openai.APIError as e:
get_logger().warning(f"Error during LLM inference: {e}")
raise
except Exception as e:
get_logger().warning(f"Unknown error during LLM inference: {e}")
raise openai.APIError from e
def _create_chat(self, deployment_id=None):
try:
if self.azure:
# using a partial function so we can set the deployment_id later to support fallback_deployments
# but still need to access the other settings now so we can raise a proper exception if they're missing
return AzureChatOpenAI(
openai_api_key=get_settings().openai.key,
openai_api_version=get_settings().openai.api_version,
azure_deployment=deployment_id,
azure_endpoint=get_settings().openai.api_base,
)
else:
# for llms that compatible with openai, should use custom api base
openai_api_base = get_settings().get("OPENAI.API_BASE", None)
if openai_api_base is None or len(openai_api_base) == 0:
return ChatOpenAI(openai_api_key=get_settings().openai.key)
else:
return ChatOpenAI(openai_api_key=get_settings().openai.key, openai_api_base=openai_api_base)
except AttributeError as e:
if getattr(e, "name"):
raise ValueError(f"OpenAI {e.name} is required") from e
else:
raise e