Python XlsxWriter - Chart Legends

Depending upon the type of chart, the data is visually represented in the form of columns, bars, lines, arcs, etc. in different colors or patterns. The chart legend makes it easy to quickly understand which color/pattern corresponds to which data series.

Working with Chart Legends

To set the legend and configure its properties such as position and font, XlsxWriter has set_legend() method. The properties are −

  • None − In Excel chart legends are on by default. The none=True option turns off the chart legend.

  • Position − Set the position of the chart legend. It can be set to top, bottom, left, right, none.

  • Font − Set the font properties (like name, size, bold, italic etc.) of the chart legend.

  • Border − Set the border properties of the legend such as color and style.

  • Fill − Set the solid fill properties of the legend such as color.

  • Pattern − Set the pattern fill properties of the legend.

  • Gradient − Set the gradient fill properties of the legend.

Some of the legend properties are set for the chart as below −

chart1.set_legend(
   {'position':'bottom', 'font': {'name':'calibri','size': 9, 'bold': True}}
)

Example

Here is the complete code to display legends as per the above characteristics −

import xlsxwriter

wb = xlsxwriter.Workbook('hello.xlsx')
worksheet = wb.add_worksheet()
chart1 = wb.add_chart({'type': 'column'})

# Add the worksheet data that the charts will refer to.
headings = ['Name', 'Phy', 'Maths']
data = [
   ["Jay", 30, 60],
   ["Mohan", 40, 50],
   ["Veeru", 60, 70],
]

worksheet.write_row(0,0, headings)
worksheet.write_row(1,0, data[0])
worksheet.write_row(2,0, data[1])
worksheet.write_row(3,0, data[2])
chart1.add_series({
   'name': '=Sheet1!$B$1',
   'categories': '=Sheet1!$A$2:$A$4',
   'values': '=Sheet1!$B$2:$B$4',
})
chart1.add_series({
   'name': ['Sheet1', 0, 2],
   'categories': ['Sheet1', 1, 0, 3, 0],
   'values': ['Sheet1', 1, 2, 3, 2],
})
chart1.set_title ({'name': 'Marklist', 'name_font':
   {'name':'Times New Roman', 'size':24}})

chart1.set_x_axis({'name': 'Students', 'name_font':
   {'name':'Arial', 'size':16, 'bold':True},})

chart1.set_y_axis({'name': 'Marks','name_font':
   {'name':'Arial', 'size':16, 'bold':True},
   'num_font':{'name':'Arial', 'italic':True}})

chart1.set_legend({'position':'bottom', 'font':
   {'name':'calibri','size': 9, 'bold': True}})

worksheet.insert_chart('B7', chart1)

wb.close()

Output

The chart shows the legend below the caption of the X axis.

Legend

In the chart, the columns corresponding to physics and maths are shown in different colors. The small colored box symbols to the right of the chart are the legends that show which color corresponds to physics or maths.

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