OpenAI Function Call API in Langchain Library
Introduction
While exploring the field of artificial intelligence, we often need to leverage existing APIs to implement specific functionalities. Recently, while exploring the Langchain library, I discovered an interesting feature: using OpenAI's function call API to perform specific operations in a chain. This not only demonstrates how to obtain structured outputs from ChatOpenAI but also how to create and execute function chains. This feature offers us a new possibility, enabling the execution of multiple functions within a chain. Through this approach, we can obtain structured outputs based on specific inputs, thus providing more accurate data for subsequent operations.
LangChain OpenAI Functions
Firstly, we need to understand how to obtain structured outputs from ChatOpenAI. In the Langchain library, there's a create_structured_output_chain function that can accept either a Pydantic class or JsonSchema for structured output formatting. This way, we can force the model to return outputs in a specific structure, facilitating subsequent processing.
For instance, we can create a Person class to describe basic information about an individual:
from langchain.pydantic_v1 import BaseModel, Field









