ReportLab Pie Chart: Displaying Category, Count, and Percentage in Labels

In ReportLab's Pie class, you can use the setLabelFont and setLabelFormat methods to customize the font and format of labels.

First, use setLabelFont to set the label font. For example, the following code sets the label font to Helvetica-Bold with a size of 10:

myPieChart.setLabelFont(Font('Helvetica-Bold', 10))

Next, use setLabelFormat to set the label format. You can use placeholders to display category, count, and percentage. For instance, the following code sets the label format to '{0}: {1} ({2:.1%})':

myPieChart.setLabelFormat('{0}: {1} ({2:.1%})')

In this format, {0} represents the category, {1} represents the count, and {2:.1%} represents the percentage (rounded to one decimal place).

Finally, call the draw method to render the pie chart. The labels will display category, count, and percentage simultaneously.