Update data_extraction_llms.ipynb

[RaviKumarSingh-Mckinsey]

in the below code section "From pydantic import Field was missing , I added that one line

from pydantic import Field

class AnswerWithSources(BaseModel):
"""An answer to the question, with sources and reasoning."""
answer: str = Field(description="Answer to question")
sources: str = Field(description="Full direct text chunk from the context used to answer the question")
reasoning: str = Field(description="Explain the reasoning of the answer based on the sources")

class ExtractedInfo(BaseModel):
"""Extracted information about the research article"""
paper_title: AnswerWithSources
paper_summary: AnswerWithSources
publication_year: AnswerWithSources
paper_authors: AnswerWithSources