How to Use Python to Highlight the Difference Value in Excel

What will you learn?

In this tutorial, you will master the art of using Python to detect and highlight varying values in an Excel spreadsheet. By automating the process of comparing data, you can efficiently pinpoint discrepancies within your dataset.

Introduction to the Problem and Solution

Handling vast datasets in Excel often involves manually spotting differences between multiple columns. However, by harnessing the power of Python, specifically with libraries like pandas and openpyxl, you can streamline this task. These libraries empower you to manipulate Excel files seamlessly within your Python scripts.


# Import necessary libraries
import pandas as pd

# Load the Excel file into a DataFrame
df = pd.read_excel('your_file.xlsx')

# Find differing values between two columns (Column A and Column B)
df['Differences'] = df.apply(lambda x: 'Mismatch' if x['Column_A'] != x['Column_B'] else '', axis=1)

# Highlight differing values in a new Excel file
df.to_excel('highlighted_differences.xlsx', index=False)

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# Copyright PHD


To address this challenge effectively: – Import the pandas library for efficient data handling. – Read the Excel file into a DataFrame using pd.read_excel(). – Compare values of ‘Column_A’ and ‘Column_B’ row-wise. – Save the updated DataFrame highlighting differences to a new Excel file.

    How do I install pandas library?

    You can install pandas via pip by executing pip install pandas in your terminal.

    Can I compare more than two columns for differences?

    Certainly! You can enhance this solution by extending the comparison logic for additional columns.

    Is it possible to customize how differences are highlighted in Excel?

    Absolutely! Define your criteria for highlighting or formatting cells based on varying values.

    Will this code work for very large Excel files?

    While functional, performance issues may arise with extensive datasets due to memory constraints; consider optimization for such scenarios.

    Can I modify this code to highlight matching values instead?

    Yes, simply adjust the lambda function’s comparison condition from inequality (!=) to equality (==).

    Are there any alternatives to using pandas for handling Excel files?

    Explore alternative libraries like xlrd or openpyxl based on your specific needs.

    How do I run this script periodically without manual intervention?

    Schedule script execution using tools like Windows Task Scheduler or cron jobs on Linux systems.

    Can I integrate this solution into a larger data processing pipeline?

    Absolutely! This script forms one step within a broader workflow encompassing data extraction, transformation, or loading tasks.

    Is there any way to visually represent these differences other than just text format changes?

    Consider leveraging visualization libraries such as matplotlib or seaborn for graphical representations of discrepancies.

    What should I do if my excel sheet has multiple worksheets but I only want one analyzed?

    Specify which sheet you wish to analyze by adding sheet_name=’specific_sheet_name’ parameter inside pd.read_excel() method


    In conclusion, harnessing Python alongside tools like pandas enables effortless identification and highlighting of varying values within an Excel spreadsheet. This automation not only saves time but also ensures precision in data analysis endeavors. For further insights and solutions related to Python programming queries, visit our website at

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