Introduction to openpyxl
Excel spreadsheets are ubiquitous in the world of business. They are used for storing, analyzing, and presenting data.
However, as the volume of data grows, Excel becomes less efficient and more prone to errors. This is where openpyxl comes in.
openpyxl is an open-source Python library used for creating and manipulating Excel files. It provides a fast and reliable way to read and write data in Excel files.
It can be used for a variety of tasks, from importing and exporting data, to appending information to existing spreadsheets. In this article, we will explore the practical use cases of openpyxl and how it can help businesses become more efficient and effective.
Practical Use Cases
Importing New Products Into a Database
In an online store, adding new products to the database can be a tedious process, especially if it involves hundreds or thousands of products. Doing it manually can consume valuable time and can lead to human errors.
In this case, openpyxl can help streamline the process. The first step is to create an Excel spreadsheet containing the necessary details of the new products.
These may include the product name, description, price, images, and other relevant information. Once the spreadsheet is ready, openpyxl can be used to import the data into the database automatically.
The process starts with opening the Excel file using openpyxl. The worksheet containing the product details can be accessed by name or index.
From there, each row can be iterated through, extracting the necessary information and inserting it into the database using Python’s built-in database API. With openpyxl, importing hundreds or thousands of products can be done in a matter of minutes, freeing up valuable time for the business owners.
Exporting Database Data Into a Spreadsheet
In marketing, user data is crucial in understanding customer behavior and creating effective campaigns. However, raw data stored in a database is not easily manageable or presentable.
To extract valuable insights from the data, it needs to be presented in a visually appealing way that is easy to interpret. This is where openpyxl comes in useful.
By using openpyxl, it is possible to extract the relevant data from the database and export it into an Excel file that can be easily manipulated and analyzed. The first step is to write a SQL query to extract the necessary data from the database.
Once the data is extracted, openpyxl can be used to create a new Excel file and populate it with the data. The process starts by opening a new Excel workbook using openpyxl.
A worksheet can be created with a designated name, and each cell can be populated with the corresponding data. By using openpyxl’s formatting options, colors, fonts, and borders, the spreadsheet can be made more visually appealing and easier to read.
By exporting database data into a spreadsheet using openpyxl, marketers can create visually appealing reports that help them analyze customer behavior, identify trends, and create targeted marketing campaigns that generate higher engagement and conversions.
Appending Information to an Existing Spreadsheet
Sometimes, businesses need to update existing spreadsheets by appending new information. For example, a business may want to keep track of the total amount spent by each customer.
Rather than creating a new spreadsheet for each transaction, openpyxl can be used to append the necessary information to an existing spreadsheet dynamically. The first step is to create an Excel file containing the existing data.
The file can be accessed using openpyxl, and the relevant worksheet can be opened. From there, each row can be iterated through, and the necessary calculations can be performed using Python’s built-in math functions.
Once the necessary calculations are done, they can be appended to the existing spreadsheet using openpyxl. An empty row can be inserted at the bottom of the worksheet, and the relevant cell values can be populated with the calculated data.
The spreadsheet can then be saved, and the new data will be appended seamlessly.
Conclusion
openpyxl is an essential tool for businesses that rely on Excel spreadsheets for managing and presenting data. With its fast and efficient data manipulation features, it can help businesses become more efficient and productive.
From importing and exporting data to appending information to existing spreadsheets, openpyxl is a versatile library that every business should consider using.
Getting Started With openpyxl
openpyxl is an open-source Python library used for creating and manipulating Excel files. In this section, we will explore how to install openpyxl and create a simple spreadsheet using the library.
Installation of openpyxl
Before getting started with openpyxl, it is necessary to install the package. Open a terminal or command prompt and run the following command to install openpyxl for Python 3.7:
“`
pip install openpyxl==2.6.2
“`
After the package is installed, it can be imported into the Python script using the following code:
“`python
import openpyxl
“`
Creating a Simple Spreadsheet
The most basic task in openpyxl is to create a new workbook and add data to it. The following code creates a new workbook and writes the strings “Hello World!” and “openpyxl is awesome!” to the first and second cells of the first sheet respectively.
Finally, the workbook is saved as “example.xlsx”. “`python
import openpyxl
# create a new workbook
workbook = openpyxl.Workbook()
# select the active sheet
sheet = workbook.active
# write data to the cells
sheet[‘A1’] = “Hello World!”
sheet[‘B1’] = “openpyxl is awesome!”
# save the workbook
workbook.save(“example.xlsx”)
“`
Reading Excel Spreadsheets With openpyxl
Besides creating Excel files with openpyxl, you can also use this library to read existing files. In this section, we will explore three methods of reading and importing data from an Excel spreadsheet.
Simple Approach to Reading an Excel Spreadsheet
The first step is to load the desired workbook using openpyxl. The following code will load the file “example.xlsx” and extract the data from the active sheet.
“`python
import openpyxl
# load the workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# read data from a cell
data = sheet[‘A1’].value
# print the data
print(data)
“`
In this example, we loaded the existing workbook “example.xlsx” and accessed the active sheet. We then extracted the data from cell “A1”.
Finally, we printed the contents of the cell to the console.
Importing Data From a Spreadsheet
If you need to import data from multiple cells in a spreadsheet, you can use the following code to retrieve data from a range of cells. “`python
import openpyxl
# load the workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# get a range of cells
cell_range = sheet[‘A1′:’B2’]
# iterate through the range
for row in cell_range:
for cell in row:
print(cell.value)
“`
In this example, we retrieved data from a range of cells by slicing the data. We used the `cell_range` variable to retrieve the data in the range A1 to B2.
We then iterated through the data and printed out the contents of each cell in the range. Manipulate Data Using Python’s Default Data Structures
Once you have imported the data from a spreadsheet, you can manipulate it using Python’s default data structures such as lists, tuples, and dictionaries.
For example, the following code converts the data we have imported into a list of tuples. “`python
import openpyxl
# load the workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# get a range of cells
cell_range = sheet[‘A1′:’B2’]
# create an empty list
data_list = []
# iterate through the range
for row in cell_range:
# create a tuple for each row
row_data = (row[0].value, row[1].value)
# add the tuple to the list
data_list.append(row_data)
# print the list
print(data_list)
“`
In this example, we iterated through the data in the range A1 to B2 and created a tuple for each row of data. We then added the tuple to the `data_list`.
Finally, we printed the `data_list` to the console.
Convert Data Into Python Classes
In Python, it is common to use classes to represent data. You can use openpyxl to convert the data you have imported from a spreadsheet into custom Python classes.
In the following example, we define two data classes, `Product` and `Review`, and use openpyxl to create objects of these classes. “`python
import openpyxl
# define the product data class
class Product:
def __init__(self, name, price):
self.name = name
self.price = price
def __str__(self):
return f”{self.name}, {self.price}”
# define the review data class
class Review:
def __init__(self, product, rating, review_text):
self.product = product
self.rating = rating
self.review_text = review_text
def __str__(self):
return f”Product: {self.product}, Rating: {self.rating}, Text: {self.review_text}”
# load the workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# get a range of cells
cell_range = sheet[‘A2′:’C3’]
# create empty lists
products = []
reviews = []
# iterate through the range
for row in cell_range:
# create product object
product_name = row[0].value
product_price = row[1].value
product = Product(product_name, product_price)
products.append(product)
# create review object
rating = row[2].value
review_text = “”
review = Review(product, rating, review_text)
reviews.append(review)
# print the products and reviews
for product in products:
print(product)
for review in reviews:
print(review)
“`
In this example, we defined two data classes, `Product` and `Review`. We then loaded the workbook and selected the active sheet.
We retrieved data from the range A2 to C3 and used the data to create objects of the `Product` and `Review` classes. Finally, we printed the objects to the console.
Writing Excel Spreadsheets With openpyxl
In this section, we will explore how to write Excel spreadsheets with openpyxl. We will cover a variety of topics, including basic spreadsheet operations, adding formulas, styles, conditional formatting, images, charts, and converting Python classes to Excel spreadsheets.
Creating a Simple Spreadsheet
The first step in writing an Excel spreadsheet with openpyxl is to load an existing workbook or create a new one. The following code creates a new workbook with a single worksheet and writes the values “Hello” and “World” to the first and second cells respectively.
Finally, the workbook is saved as “example.xlsx”. “`python
import openpyxl
# create a new workbook
workbook = openpyxl.Workbook()
# select the active sheet
sheet = workbook.active
# write data to the cells
sheet[‘A1’] = “Hello”
sheet[‘B1’] = “World”
# save the workbook
workbook.save(“example.xlsx”)
“`
Basic Spreadsheet Operations
openpyxl provides several methods to manipulate Excel spreadsheets. For example, you can use the following code to merge cells, set column width, and set row height.
“`python
import openpyxl
# load an existing workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# merge cells
sheet.merge_cells(‘A1:B1’)
# set column width
sheet.column_dimensions[‘A’].width = 10
# set row height
sheet.row_dimensions[1].height = 30
# save the workbook
workbook.save(“example.xlsx”)
“`
In this example, we loaded the existing workbook “example.xlsx”, selected the active sheet, merged cells A1 and B1, set the width of column A to 10, and set the height of row 1 to 30.
Adding Formulas
openpyxl allows you to write formulas in Excel cells and calculate the results automatically. The following code adds a formula to cell C1 that multiplies the values in cells A1 and B1 and calculates the result.
“`python
import openpyxl
# load an existing workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# write a formula
sheet[‘C1’] = “=A1*B1”
# calculate the result
workbook.calculate_computed_formulas()
# save the workbook
workbook.save(“example.xlsx”)
“`
In this example, we added a formula to cell C1 that multiplies the values in cells A1 and B1. We then used the `calculate_computed_formulas()` method to calculate the result and finally saved the workbook.
Adding Styles
openpyxl allows you to apply cell styles to Excel spreadsheets. You can modify the font, fill, borders, and alignment of cells, making your spreadsheet more visually appealing.
The following code adds styles to cells A1 and B1, changing the font to bold and the fill color to green. “`python
import openpyxl
from openpyxl.styles import Font, PatternFill
# load an existing workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# add font style
font = Font(bold=True)
sheet[‘A1’].font = font
# add fill style
fill = PatternFill(start_color=’008000′, end_color=’008000′, fill_type=’solid’)
sheet[‘B1’].fill = fill
# save the workbook
workbook.save(“example.xlsx”)
“`
In this example, we added font and fill styles to cells A1 and B1. We used the `Font` and `PatternFill` classes from the `openpyxl.styles` module to modify the font and fill properties of the cells.
Conditional Formatting
openpyxl allows you to apply conditional formatting to Excel spreadsheets. This allows you to highlight cells based on specific criteria, such as cell values or ranges of values.
The following code adds a conditional format to highlight cells in column A that have a value greater than 10. “`python
import openpyxl
from openpyxl.styles import PatternFill, ColorScaleRule
# load an existing workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# add conditional formatting
rule = ColorScaleRule(start_type=’num’, start_value=10, start_color=’FF0000′, end_type=’min’, end_value=None, end_color=’FFFFFF’)
for cell in sheet[‘A’]:
cell.conditional_formatting.add(rule)
# save the workbook
workbook.save(“example.xlsx”)
“`
In this example, we added a conditional format to highlight cells in column A that have a value greater than 10. We used the `ColorScaleRule` class to define the rule, and the `add()` method to add the rule to each cell in column A.
Adding Images
openpyxl allows you to add images to Excel spreadsheets. You can adjust the size and position of the image, making your spreadsheet more visually appealing.
The following code adds an image to cell A1 of the active sheet. “`python
import openpyxl
from openpyxl.drawing.image import Image
# load an existing workbook
workbook = openpyxl.load_workbook(“example.xlsx”)
# select the active sheet
sheet = workbook.active
# add an image
img = Image(‘myimage.png’)
sheet.add_image(img, ‘A1’)
# save the workbook
workbook.save(“example.xlsx”)
“`
In this example, we added an image to cell A1 of the active sheet. We used the `Image` class from the `openpyxl.drawing.image` module to load the image file