Python openpyxl – Add colored border to cell in spreadsheet

In this post we will be creating a Python script that will add a colored border to a cell within a spreadsheet using openpyxl. Openpyxl is a library that allows us to interact with Excel files in Python. It provides a range of tools for reading, writing, manipulating, and formatting Excel data. This makes it a useful tool for data analysis and reporting tasks.

See the sample of Python code below where we use the openpyxl library to add a colored border around a cell within an already existing Excel spreadsheet. We start by loading our existing Excel file called example.xlsx and assign it to a variable named workbook. Next we retrieve the active worksheet from the workbook. A new Border object is then created with Side objects for each side. Here the border style for each side is set to ‘double’ and a color is also assigned. We then select cell B2 of the worksheet and assign it to the variable cell. The border style for our cell is then set to the border_style defined earlier. Finally the changes made to the Excel file are saved using the save() method.

import openpyxl
from openpyxl.styles import Border, Side

workbook = openpyxl.load_workbook('example.xlsx')

worksheet = workbook.active

border_style = Border(left=Side(style='double', color='FF0000'),
                      right=Side(style='double', color='00FF00'),
                      top=Side(style='double', color='0095FF'),
                      bottom=Side(style='double', color='FF00DD'))

cell = worksheet['B2']
cell.border = border_style

workbook.save('example.xlsx')

See an image of the colored border for our cell below.

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