Creating objects using Pydantic

openai_schema.py

import openai
from pydantic import BaseModel, Field

class OpenAISchema(BaseModel):

    @classmethod
    @property
    def openai_schema(cls):
        schema = cls.schema()
        return {
            "name": schema["title"],
            "description": schema["description"],
            "parameters": schema
        }

    @classmethod
    def from_response(cls, completion, throw_error=True):
        message = completion.choices[0].message

        if throw_error:
            assert "function_call" in message, "No function call detected"
            assert message["function_call"]["name"] == cls.openai_schema["name"], "Function name does not match"

        function_call = message["function_call"]
        arguments = json.loads(function_call["arguments"])
        return cls(**arguments)
    

# Note: The docstring and the description are used as part of the prompt, detailed desc and docs 
# can be used to provide more information about the function

class Arguments(OpenAISchema):
    """Arguments to add"""

    a: int = Field(..., description="First argument")
    b: int = Field(..., description="Second argument")


completion = openai.ChatCompletion.create(
        model="gpt-3.5-turbo-0613",
        temperature=0,
        functions=[Arguments.openai_schema],
        messages=[
            {
                "role": "system",
                "content": "You must use the `arguments` function instead of adding yourself.",
            },
            {
                "role": "user",
                "content": "What is 6+3, use the arguments",
            },
        ],
    )

Arguments.from_response(completion)
# Arguments(a=6, b=3)