Codestral with self-correction : Failed import of pydantic v1

[gh4ag]

Context

Cookbook recipe: "Codestral with self-correction"

In https://github.com/mistralai/cookbook/blob/main/third_party/langchain/langgraph_code_assistant_mistral.ipynb

Issue

When running the notebook with the predefined !pip install, the following import fails:

from langchain_core.pydantic_v1 import BaseModel, Field

Fix

Replace from langchain_core.pydantic_v1 import BaseModel, Field with the following

from pydantic.v1 import BaseModel, Field

Test

Notebook on Colab run successfully after fix implementation

[yaowubarbara]

The langchain_core.pydantic_v1 module was removed in recent versions of LangChain. I also noticed several other unused imports in the same cell (itemgetter, RunnablePassthrough, PromptTemplate). Cleaning all of them up in a PR along with #231.