Python XlsxWriter ChartSheet watermark does not work

Question

I use python xlsxwriter to create PDF tables and graphs. There is a option to put watermark pictures by using the header. This works fine for worksheets but it does not work for chartsheets. The header text is shown on both worksheets and chartsheets. The header image is only shown on the worksheet.

Anyone knows how to get a watermark on a chartsheet?

Here is an code example for this

    #######################################################################
#
# An example of creating an Excel chart in a chartsheet with Python
# and XlsxWriter.
#
# SPDX-License-Identifier: BSD-2-Clause
# Copyright 2013-2023, John McNamara, jmcnamara@cpan.org
#
import xlsxwriter

workbook = xlsxwriter.Workbook("chartsheet.xlsx")

# Add a worksheet to hold the data.
worksheet = workbook.add_worksheet()

worksheet.set_header('&C&G&LTEXTISVISIBLE', {'image_center': 'watermark_draft.png'})

# Add a chartsheet. A worksheet that only holds a chart.
chartsheet = workbook.add_chartsheet()

chartsheet.set_header('&C&G&LTEXTISVISIBLE', {'image_center': 'watermark_draft.png'})

# Add a format for the headings.
bold = workbook.add_format({"bold": 1})

# Add the worksheet data that the charts will refer to.
headings = ["Number", "Batch 1", "Batch 2"]
data = [
    [2, 3, 4, 5, 6, 7],
    [10, 40, 50, 20, 10, 50],
    [30, 60, 70, 50, 40, 30],
]

worksheet.write_row("A1", headings, bold)
worksheet.write_column("A2", data[0])
worksheet.write_column("B2", data[1])
worksheet.write_column("C2", data[2])


# Create a new bar chart.
chart1 = workbook.add_chart({"type": "bar"})

# Configure the first series.
chart1.add_series(
    {
        "name": "=Sheet1!$B$1",
        "categories": "=Sheet1!$A$2:$A$7",
        "values": "=Sheet1!$B$2:$B$7",
    }
)

# Configure a second series. Note use of alternative syntax to define ranges.
chart1.add_series(
    {
        "name": ["Sheet1", 0, 2],
        "categories": ["Sheet1", 1, 0, 6, 0],
        "values": ["Sheet1", 1, 2, 6, 2],
    }
)

# Add a chart title and some axis labels.
chart1.set_title({"name": "Results of sample analysis"})
chart1.set_x_axis({"name": "Test number"})
chart1.set_y_axis({"name": "Sample length (mm)"})

# Set an Excel chart style.
chart1.set_style(11)

# Add the chart to the chartsheet.
chartsheet.set_chart(chart1)

# Display the chartsheet as the active sheet when the workbook is opened.
chartsheet.activate()

workbook.close()

Answer 1

It turns out there was a bug in XlsxWriter that prevented header image from being added (fully) to chartsheets. That is fixed now on the GitHub main: https://github.com/jmcnamara/XlsxWriter