openpyxl Part 20 – Pie Charts

In the previous part we created a line chart. In this part we’ll create pie charts. We’ll be using the wb4.xlsx workbook to start with. As you remember, it contains random data:

	2015	2016	2017	2018	2019
tables	1343	1113	1139	1761	1827
closets	1572	1492	1637	1067	1824
chairs	1097	1752	1991	1512	1587

As the data is random, your data is different if you were following along. Here’s the line chart we generated for the data:

It actually sits on top of the bar chart that we created even before:

In this article we’ll create a pie chart that will represent the sales of the three products in 2015. Let’s start by loading the workbook:

>>> from openpyxl import load_workbook
>>> workbook = load_workbook(filename="wb4.xlsx")
>>> sheet = workbook.active

Now we need the PieChart and Reference classes:

>>> from openpyxl.chart import PieChart, Reference

Let’s create the chart and the references:

>>> chart = PieChart()
>>> data = Reference(worksheet=sheet, min_col=2, min_row=1, max_row=4) 
>>> labels = Reference(worksheet=sheet, min_col=1, min_row=2, max_row=4)

Let’s set the title, add the data to the chart and set the categories:

>>> chart.title = '2015 Sales'
>>> chart.add_data(data, titles_from_data=True)
>>> chart.set_categories(labels)

Finally let’s add the chart and save the workbook as a new file:

>>> sheet.add_chart(chart, 'N10')
>>> workbook.save("wb4b.xlsx")

If you now open the new file, you will see the pie chart next to the line chart we created before:

There are lots of other charts that you can create. Some of the fanciest ones are 3D charts. We’ll have a look at some in the next part of the openpyxl series.