Bird
0
0

Identify the error in this LangSmith tracing setup code:

medium📝 Debug Q14 of 15
LangChain - LangSmith Observability
Identify the error in this LangSmith tracing setup code: 
from langchain.chat_models import ChatOpenAI
from langchain.callbacks import LangChainTracer

tracer = LangChainTracer
llm = ChatOpenAI(callbacks=[tracer])
ALangChainTracer is not imported correctly
BLangChainTracer is assigned without parentheses, missing instantiation
CCallbacks list should be empty for tracing
DChatOpenAI does not accept callbacks parameter
Step-by-Step Solution
Solution:

  1. Step 1: Check LangChainTracer assignment

    tracer = LangChainTracer misses parentheses, so tracer is a class, not an instance.

  2. Step 2: Analyze usage in callbacks

    Passing callbacks=[tracer] passes the class instead of an instance, causing a runtime error when callbacks are used.

  3. Final Answer:

    LangChainTracer is assigned without parentheses, missing instantiation -> Option B

  4. Quick Check:

    Instantiate with () to create tracer object [OK]
Quick Trick: Always instantiate classes with () before use [OK]
Common Mistakes:
MISTAKES
  • Assigning class instead of instance
  • Calling instance as function
  • Ignoring callbacks parameter usage

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More LangChain Quizzes
Evaluation and Testing - LangSmith evaluators - Quiz 4medium Evaluation and Testing - A/B testing prompt variations - Quiz 2easy Evaluation and Testing - A/B testing prompt variations - Quiz 4medium Evaluation and Testing - Creating evaluation datasets - Quiz 3easy Evaluation and Testing - Regression testing for chains - Quiz 10hard LangGraph for Stateful Agents - Checkpointing and persistence - Quiz 3easy LangSmith Observability - Feedback collection and annotation - Quiz 11easy Production Deployment - Monitoring and alerting in production - Quiz 9hard Production Deployment - Streaming in production - Quiz 2easy Production Deployment - Streaming in production - Quiz 9hard