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How to Build a CSV Comparison Tool That Highlights Every Changed Cell in Python

Read two CSV files with DictReader, compare cell by cell, and return a list of dictionaries describing each changed cell using only the standard library.

csv comparison diff

Python

import csv
from pathlib import Path

def csv_cell_diff(file_a: str, file_b: str) -> list[dict]:
    rows_a = list(csv.DictReader(Path(file_a).open('r', newline='')))
    rows_b = list(csv.DictReader(Path(file_b).open('r', newline='')))
    if not rows_a or not rows_b:
        return []
    columns = list(rows_a[0].key…

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How to Build a CSV Comparison Tool That Highlights Every Changed Cell in Python

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