Formatting Cells using openpyxl in Python
Last Updated :
22 Aug, 2024
When it comes to managing Excel files programmatically, Python offers a powerful tool in the form of the openpyxl library. This library not only allows us to read and write Excel documents but also provides extensive support for cell formatting. From fonts and colors to alignment and borders, openpyxl makes it easy to customize our Excel sheets to fit our needs precisely. In this article, we will learn how to format cells using OpenPyxl
Getting Started with openpyxl
Formatting cells in Excel using the openpyxl library involves several steps that allow us to customize the appearance and functionality of our spreadsheets programmatically. Here's a step-by-step guide to help us get started:
Install openpyxl
First, we need to install the openpyxl library in our Python environment.
pip install openpyxl
Create a Workbook
We can create a work book by creating an instance of Workbook class.
Python
from openpyxl import Workbook
# Create a Workbook
wb = Workbook()
# Get the work sheet
sheet = wb.active
# Modify the cells in the work sheet
sheet["A1"] = "hello"
sheet["B1"] = "geek!"
# Save the workbook
wb.save(filename="hello_geek.xlsx")
Each work book is created with at least one work sheet that we can get using the Workbook.active property. Here, we are modifying the value in the A1 and B1 cell. Lastly saving the file to get the excel file named "hello_geek.xlsx".
Output
Create a work book using openpyxlRenaming the sheet
Python
# ...
# Rename the worksheet
sheet.title = "Geek Sheet"
# ...
Output
Rename the sheet using openpyxlFont Formatting
To format the font, we need to import Font class from openpyxl.styles. The Font class provides all the functionality to format cell. Let us customize the font style, size, color, and more to enhance text appearance.
Python
# ...
from openpyxl.styles import Font
# ...
# Example: Tomato-colored, bold, and italic text
sheet['A1'].font = Font(
name='Calibri',
bold=True,
italic=True,
size=14,
color="FF6347"
)
# ...
Output
Format cell using openpyxlHow to Fill Color in Cell
We can fill color using the PatternFill class from the openpyxl.styles. Here, we are changing the background color of cells to Yellow.
Python
# ...
from openpyxl.styles import PatternFill
# ...
# Example: Solid yellow fill
sheet['B1'].fill = PatternFill(start_color="FFFF00", end_color="FFFF00", fill_type="solid")
# ...
Output
Fill color in cell using openpyxlHow to Adjust Cell Alignment
We can adjust the alignment of the text within cells using the Alignment class from openpyxl.styles
Python
# ...
from openpyxl.styles import Alignment
# ...
# Center text horizontally and vertically
sheet['A3'] = "I'm vertically and Horizontally Centered"
sheet['A3'].alignment = Alignment(horizontal='center', vertical='center')
# ...
Output
Change alignment of text in a cell using openpyxlHow to change Border Styles of a cell
We can modify borders of cells to define areas clearly by using the Border and Side classes from the openpyxl.styles.
Python
# ...
from openpyxl.styles import Border, Side
# ...
border_thick = Side(style='thick')
border_thin = Side(style='thin')
borded_dashed = Side(style='dashed')
border_dotted = Side(style='dotted')
# Apply different border styles
sheet['C1'].border = Border(top=border_thick, left=border_thin, right=borded_dashed, bottom=border_dotted)
# ...
Output
Border formatting using openpyxlStep 8: Number Formatting
Apply number formats for displaying financial figures, dates, or other formatted numbers.
Python
# ...
sheet['A3'] = 4312345.6789
sheet['A3'].number_format = '#,##0.00'
sheet['B3'] = "2024-01-01"
sheet['B3'].number_format = 'yyyy-mm-dd'
# ...
Output
Number formatting using OpenpyxlHow to save the Workbook
We can use the Workbook.save() method to save the workbook with a custom name.
Python
# ...
wb.save("hello_geek.xlsx")
Complete Code:
The code demonstrates how to use openpyxl to create and format an Excel sheet. We can enhance this by adding more complex data analysis, charts, or additional formatting to meet specific business needs. This example serves as a foundational guide to creating professional, formatted reports with Python.
Python
from openpyxl import Workbook
from openpyxl.styles import Font, PatternFill, Alignment, Border, Side
# Create a workbook
workbook = Workbook()
# Get the active sheet
sheet = workbook.active
# Change content in cell
sheet['A1'] = "hello"
sheet['B1'] = "geek"
sheet.title = "Geek Sheet"
# Example: Tomato-colored, bold, and italic text
sheet['A1'].font = Font(
name='Calibri',
bold=True,
italic=True,
size=14,
color="FF6347"
)
# Example: Solid yellow fill
sheet['B1'].fill = PatternFill(start_color="FFFF00", end_color="FFFF00", fill_type="solid")
# Change the allignment
sheet['C1'] = "I'm vertically and Horizontally Centered"
sheet['C1'].alignment = Alignment(horizontal='center', vertical='center')
# Set border properties
border_thick = Side(style='thick')
border_thin = Side(style='thin')
borded_dashed = Side(style='dashed')
border_dotted = Side(style='dotted')
# Apply different border styles
sheet['C1'].border = Border(top=border_thick, left=border_thin, right=borded_dashed, bottom=border_dotted)
# Format number to 2 decimal places
sheet['A3'] = 4312345.6789
sheet['A3'].number_format = '#,##0.00'
# Format date
sheet['B3'] = "2024-01-01"
sheet['B3'].number_format = 'yyyy-mm-dd'
# Save the work book
workbook.save("hello_geek.xlsx")
Output
Modify Excel Sheet using OpenpyxlConclusion
By following these steps, we can fully customize our Excel files using Python. This process not only enhances the presentation of the data but also allows for better readability and professional-quality reports. openpyxl is a powerful tool for anyone looking to automate or enhance their Excel-related tasks programmatically.
Similar Reads
Adding Conditional Formatting to Excel Using Python Openpyxl
Adding conditional formatting using openpyxl is an easy and straightforward process. While working with Excel files, conditional formatting is useful for the visualization of trends in the data, highlighting crucial data points, and making data more meaningful and understandable. In this article, we
5 min read
Formatting containers using format() in Python
Let us see how to format containers that were accessed through __getitem__ or getattr() using the format() method in Python. Accessing containers that support __getitem__a) For Dictionaries C/C++ Code # creating a dictionary founder = {'Apple': 'Steve Jobs', 'Microsoft': 'Bill Gates'} # formatting p
1 min read
Python Modulo String Formatting
In Python, a string of required formatting can be achieved by different methods. Some of them are; 1) Using % 2) Using {} 3) Using Template Strings In this article the formatting using % is discussed. The formatting using % is similar to that of 'printf' in C programming language. %d - integer %f -
2 min read
Python code formatting using Black
Writing well-formatted code is very important, small programs are easy to understand but as programs get complex they get harder and harder to understand. At some point, you can’t even understand the code written by you. To avoid this, it is needed to write code in a readable format. Here Black come
3 min read
Creating Charts using openpyxl
Charts are a powerful way to visualize data, making it easier to analyze and present information. While working with Excel files in Python, the library openpyxl comes into the picture and can be used as a tool for automating tasks like reading data, writing data, formatting cells, and of course crea
7 min read
Excel Automation with Openpyxl in Python
Excel is a powerful tool that allows you to store, manipulate and analyze data. It is widely used in various industries for data analysis and reporting. However, as the size of the data increases, Excel becomes slow and it takes a lot of time to perform complex operations. This is where Python comes
4 min read
Merge and Unmerge Excel Cells using openpyxl in Python
In this article, we are going to learn about Python programs to merge and unmerge excel cells using openpyxl. IntroductionOpenpyxl is a Python library commonly used for reading and writing Excel Files. In this article, we will be using this library to merge cells in Excel. Merging is helpful when we
4 min read
What does %s mean in a Python format string?
In Python, the %s format specifier is used to represent a placeholder for a string in a string formatting operation. It allows us to insert values dynamically into a string, making our code more flexible and readable. This placeholder is part of Python's older string formatting method, using the % o
3 min read
Reading an excel file using Python openpyxl module
Openpyxl is a Python library for reading and writing Excel (with extension xlsx/xlsm/xltx/xltm) files. The Openpyxl Module allows Python programs to read and modify Excel files. For example, users might have to go through thousands of rows and pick out a few handfuls of information to make small cha
3 min read
How to get sheet names using openpyxl - Python
The openpyxl library is widely used to handle excel files using Python. Often when dealing with excel files one might have noticed multiple sheets. The sheets are normally mentioned in the bottom left corner of the screen. One can install this library by running the following command. pip install op
2 min read