Manage Chart Workbooks in Presentations with Python

What this page is about

Discover Aspose.Slides for Python via .NET: effortlessly manage chart workbooks in PowerPoint and OpenDocument formats to streamline your presentation data.

Overview

This article explains how to work with chart workbooks in Aspose.Slides. It shows how to read and write chart data through workbook streams, use workbook cells as chart data labels, access worksheet collections, and specify the data source type for chart values.

It also covers working with external workbooks as chart data sources. The examples demonstrate how to create and assign an external workbook, retrieve the path of an external workbook linked to a chart, and edit chart data when the workbook is available.

For workbook cells that represent missing data, see Control the Display of Empty Cells for the difference between an empty cell and zero, and a line-chart comparison of the available display modes.

Include Data from Hidden Rows and Columns

Use Chart.plot_visible_cells_only to control whether a chart plots data from hidden worksheet rows and columns. Set it to True to plot only visible cells, or False to include both visible and hidden cells. This setting controls chart plotting; it does not hide or unhide worksheet rows or columns.

Download hidden-source-data.pptx and place it in the working directory. Its first slide contains a column chart as the first shape. The embedded worksheet, Sheet1, contains the following source range, A1:C4. Row 3 and column C are hidden, but their cells still contain values.

Worksheet row	A: Month	B: Retail	C: Wholesale (hidden column)
2	January	10	30
3 (hidden row)	February	40	60
4	March	20	50

Access source cells through ChartData.chart_data_workbook and read ChartDataCell.is_hidden to inspect their hidden status. This property is read-only. In this file, B2 is visible, B3 belongs to the hidden row, and C2 belongs to the hidden column; the example prints False, True, and True, respectively.

For this example, refresh the chart data after changing the plotting setting: retain the embedded workbook with read_workbook_stream and reload it with write_workbook_stream. When including all cells, also use set_range to restore the complete range, including the hidden February category. Simply changing the flag is insufficient to refresh this sample’s cached chart data and category labels.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation("hidden-source-data.pptx") as presentation:
    slide = presentation.slides[0]

    if len(slide.shapes) > 0 and isinstance(slide.shapes[0], charts.Chart):
        chart = slide.shapes[0]
        workbook = chart.chart_data.chart_data_workbook
        print(f"B2 hidden: {workbook.get_cell(0, 'B2').is_hidden}")
        print(f"B3 hidden: {workbook.get_cell(0, 'B3').is_hidden}")
        print(f"C2 hidden: {workbook.get_cell(0, 'C2').is_hidden}")

        workbook_stream = chart.chart_data.read_workbook_stream()
        for visible_only in [True, False]:
            chart.plot_visible_cells_only = visible_only

            # Refresh the chart data from the embedded workbook.
            workbook_stream.seek(0)
            chart.chart_data.write_workbook_stream(workbook_stream)
            if not visible_only:
                # Restore the complete source range, including hidden categories.
                chart.chart_data.set_range("Sheet1!$A$1:$C$4")

            presentation.save(f"hidden_cells_{visible_only}.pptx", slides.export.SaveFormat.PPTX)
    else:
        print("The first shape is not a chart.")

The example saves hidden_cells_True.pptx with only the visible Retail values (10 and 20), and hidden_cells_False.pptx with all six values. The images below were rendered from the saved presentations after reopening them; both files preserve their assigned plotting setting. Row 3 and column C remain hidden in both embedded workbooks.

Only visible cells (`True`)	All cells (`False`)

A hidden cell containing a value is different from an empty cell. Chart.display_blanks_as controls how missing values are displayed; it does not include or exclude hidden source data. See Control the Display of Empty Cells for an example.

Read and Write Chart Data from a Workbook

Aspose.Slides for Python via .NET provides the read_workbook_stream and write_workbook_stream methods that allow you to read and write chart data workbooks (containing chart data edited with Aspose.Cells). Note that the chart data has to be organized in the same manner or must have a structure similar to the source.

This example opens chart.pptx, which must contain a chart as the first shape on its first slide. It reads the embedded workbook into a stream, clears the existing series and categories, and writes the same workbook back. The changes remain in memory; the example does not save the presentation.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation("chart.pptx") as presentation:
    slide = presentation.slides[0]

    if len(slide.shapes) > 0 and isinstance(slide.shapes[0], charts.Chart):
        chart = slide.shapes[0]
        chart_data = chart.chart_data
        workbook_stream = chart_data.read_workbook_stream()

        chart_data.series.clear()
        chart_data.categories.clear()

        workbook_stream.seek(0)
        chart_data.write_workbook_stream(workbook_stream)
    else:
        print("The first shape is not a chart.")

Validate Chart Layout After Workbook Modification

When you replace an embedded workbook with a modified one, the chart retains its original series and category collections. This mismatch can cause Chart.validate_chart_layout to fail with an index-out-of-range error. Clear the existing series and categories before writing the updated workbook back to the chart. This example requires chart.pptx with a chart as the first shape on its first slide. The comment marks where workbook editing would occur; the runnable example writes the original workbook back and validates the layout in memory.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation("chart.pptx") as presentation:
    slide = presentation.slides[0]

    if len(slide.shapes) > 0 and isinstance(slide.shapes[0], charts.Chart):
        chart = slide.shapes[0]
        chart_data = chart.chart_data
        workbook_stream = chart_data.read_workbook_stream()

        # Modify the workbook stream here, for example, using Aspose.Cells.

        chart_data.series.clear()
        chart_data.categories.clear()

        workbook_stream.seek(0)
        chart_data.write_workbook_stream(workbook_stream)
        chart.validate_chart_layout()
    else:
        print("The first shape is not a chart.")

Clearing the collections removes stale data references before the workbook is written back. Rebuild any required series and category mappings for the updated workbook before using the chart.

Set a Workbook Cell as a Chart Data Label

You can use text from workbook cells as chart data labels. The following steps show how to link the labels in a bubble chart to cells in its data workbook.

Create an instance of the Presentation class.
Access the first slide by its zero-based index.
Add a bubble chart with default data.
Access the chart series.
Set the workbook cell as a data label.
Save the presentation.

This example opens chart2.pptx, which must contain at least one slide, and adds a bubble chart with default data. It uses cells A10:A12 on worksheet 0 for the first three labels in the first series, enables labels from cells, and saves the result to resultchart.pptx.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation("chart2.pptx") as presentation:
    slide = presentation.slides[0]

    chart = slide.shapes.add_chart(charts.ChartType.BUBBLE, 50, 50, 600, 400, True)
    series = chart.chart_data.series[0]
    workbook = chart.chart_data.chart_data_workbook

    series.labels.default_data_label_format.show_label_value_from_cell = True
    series.labels[0].value_from_cell = workbook.get_cell(0, "A10", "Label 0 cell value")
    series.labels[1].value_from_cell = workbook.get_cell(0, "A11", "Label 1 cell value")
    series.labels[2].value_from_cell = workbook.get_cell(0, "A12", "Label 2 cell value")

    presentation.save("resultchart.pptx", slides.export.SaveFormat.PPTX)

Manage Worksheets

The ChartDataWorkbook.worksheets property provides access to the worksheets in a chart workbook. This example creates a pie chart with default data and prints each worksheet name to the console.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    chart = slide.shapes.add_chart(charts.ChartType.PIE, 50, 50, 400, 500)
    workbook = chart.chart_data.chart_data_workbook

    for worksheet in workbook.worksheets:
        print(worksheet.name)

Specify the Data Source Type

This example creates a 3D column chart with default data and sets two series names using different data sources. The first name uses a string literal; the second uses cell C1 on worksheet 0. The DataSourceType enumeration selects the source for each name. The result is saved to pres.pptx.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    chart = slide.shapes.add_chart(charts.ChartType.COLUMN_3D, 50, 50, 600, 400, True)
    literal_name = chart.chart_data.series[0].name

    literal_name.data_source_type = charts.DataSourceType.STRING_LITERALS
    literal_name.data = "LiteralString"

    cell_name = chart.chart_data.series[1].name
    name_cell = chart.chart_data.chart_data_workbook.get_cell(0, "C1", "NewCell")
    cell_name.data_source_type = charts.DataSourceType.WORKSHEET
    cell_name.data = name_cell

    presentation.save("pres.pptx", slides.export.SaveFormat.PPTX)

Detect Unsupported Embedded Workbook Formats

Aspose.Slides does not support the Excel binary workbook (.xlsb) format that can be embedded in some charts. You can use the embedded_workbook_type property on ChartData together with the WorkbookType enumeration to detect unsupported formats and skip those charts. This example inspects the shapes on the first slide of sample.pptx, skips non-chart shapes, and prints a diagnostic message for each chart with an embedded .xlsb workbook.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation("sample.pptx") as presentation:
    slide = presentation.slides[0]

    for shape in slide.shapes:
        if not isinstance(shape, charts.Chart):
            continue

        chart_data = shape.chart_data
        is_internal_workbook = chart_data.data_source_type == charts.ChartDataSourceType.INTERNAL_WORKBOOK
        is_binary_macro = chart_data.embedded_workbook_type == charts.WorkbookType.WORKBOOK_BINARY_MACRO

        if is_internal_workbook and is_binary_macro:
            print("Skipping a chart with an unsupported .xlsb workbook.")
            continue

        # Read or modify supported chart workbook data here.

External Workbook

Aspose.Slides supports using external workbooks as a data source for charts.

Create an External Workbook

Use read_workbook_stream and set_external_workbook to export an embedded chart workbook to a file and link the chart to that external workbook.

This example creates a pie chart with default data, writes its workbook to externalWorkbook1.xlsx, and closes the output stream before assigning the file as the chart data source. It saves the linked presentation to externalWorkbook.pptx.

from pathlib import Path
import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    chart = slide.shapes.add_chart(charts.ChartType.PIE, 50, 50, 400, 600)
    workbook_path = str(Path("externalWorkbook1.xlsx").resolve())

    workbook_stream = chart.chart_data.read_workbook_stream()
    workbook_data = workbook_stream.read()
    with open(workbook_path, "wb") as file_stream:
        file_stream.write(workbook_data)

    chart.chart_data.set_external_workbook(workbook_path)
    presentation.save("externalWorkbook.pptx", slides.export.SaveFormat.PPTX)

Set an External Workbook

Using the set_external_workbook method, you can assign an external workbook to a chart as its data source. This method can also be used to update a path to the external workbook (if the latter has been moved).

While you cannot edit the data in workbooks stored in remote locations or resources, you can still use such workbooks as an external data source. If the relative path for an external workbook is provided, it gets converted to a full path automatically.

This example requires externalWorkbook.xlsx in the working directory. Its worksheet named Sheet1 must contain a series name in B1, category names in A2:A4, and numeric values in B2:B4. The example creates a pie chart, links the workbook, and uses set_range to map A1:B4 to one series and three categories. It saves the result to Presentation_with_externalWorkbook.pptx.

from pathlib import Path
import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    chart = slide.shapes.add_chart(charts.ChartType.PIE, 50, 50, 400, 600, True)
    chart_data = chart.chart_data
    workbook_path = str(Path("externalWorkbook.xlsx").resolve())

    chart_data.set_external_workbook(workbook_path)
    chart_data.set_range("Sheet1!$A$1:$B$4")

    presentation.save("Presentation_with_externalWorkbook.pptx", slides.export.SaveFormat.PPTX)

The update_chart_data parameter of set_external_workbook controls whether the workbook is loaded.

When update_chart_data is False, only the workbook path is updated. The chart data is not loaded or updated from the target workbook, so the workbook can be unavailable.
When update_chart_data is True, the chart data is updated from the target workbook.

The following example assigns a placeholder URL with update_chart_data set to False. It retains the pie chart’s default data and saves the presentation without loading the unavailable workbook.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    chart = slide.shapes.add_chart(charts.ChartType.PIE, 50, 50, 400, 600, True)

    chart.chart_data.set_external_workbook("https://example.com/unavailable-workbook.xlsx", False)
    presentation.save("SetExternalWorkbookWithUpdateChartData.pptx", slides.export.SaveFormat.PPTX)

Get the External Data Source Workbook Path of a Chart

To identify the workbook linked to a chart, first check whether the chart uses an external data source. If it does, you can retrieve the workbook path by following these steps.

Create an instance of the Presentation class.
Access the first slide by its zero-based index.
Check that the first shape is a chart.
Read the chart data source type.
If the source is an external workbook, read its path.

This example opens externalWorkbook.pptx, created in the earlier example, and inspects the first shape on the first slide. If it is a chart linked to an external workbook, the example prints external_workbook_path to the console. It then saves a copy of the presentation to Result.pptx.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation("externalWorkbook.pptx") as presentation:
    slide = presentation.slides[0]

    if len(slide.shapes) > 0 and isinstance(slide.shapes[0], charts.Chart):
        chart = slide.shapes[0]
        chart_data = chart.chart_data
        if chart_data.data_source_type == charts.ChartDataSourceType.EXTERNAL_WORKBOOK:
            print(chart_data.external_workbook_path)
        else:
            print("The chart does not use an external workbook.")
    else:
        print("The first shape is not a chart.")

    presentation.save("Result.pptx", slides.export.SaveFormat.PPTX)

Edit Chart Data

You can edit the data in external workbooks the same way you make changes to the contents of internal workbooks. When an external workbook cannot be loaded, an exception is thrown.

This example requires presentation.pptx with a chart as the first shape on the first slide and an accessible external workbook. It sets the cell-backed value of the first data point in the first series to 100 and saves the presentation to presentation_out.pptx. Editing cell values can update the linked external XLSX file, so use a copy if you need to preserve the original workbook.

import aspose.slides as slides
import aspose.slides.charts as charts

with slides.Presentation("presentation.pptx") as presentation:
    slide = presentation.slides[0]

    if len(slide.shapes) > 0 and isinstance(slide.shapes[0], charts.Chart):
        chart = slide.shapes[0]
        series = chart.chart_data.series
        if len(series) > 0 and len(series[0].data_points) > 0:
            value_cell = series[0].data_points[0].value.as_cell
            if value_cell is not None:
                value_cell.value = 100
                presentation.save("presentation_out.pptx", slides.export.SaveFormat.PPTX)
            else:
                print("The first data point is not linked to a workbook cell.")
        else:
            print("The chart has no data points to edit.")
    else:
        print("The first shape is not a chart.")

Recover a Workbook from the Chart Cache

If a chart uses an external workbook that is missing or unavailable, Aspose.Slides can reconstruct the chart workbook from the data cached in the presentation. Create LoadOptions, configure its spreadsheet_options, and set SpreadsheetOptions.recover_workbook_from_chart_cache to True before opening the presentation.

The following Python example opens presentation.pptx, whose first shape on the first slide must be a chart referencing an unavailable external workbook, and accesses the recovered data through Chart.chart_data and ChartData.chart_data_workbook:

import aspose.slides as slides
import aspose.slides.charts as charts

load_options = slides.LoadOptions()
load_options.spreadsheet_options.recover_workbook_from_chart_cache = True

with slides.Presentation("presentation.pptx", load_options) as presentation:
    slide = presentation.slides[0]

    if len(slide.shapes) > 0 and isinstance(slide.shapes[0], charts.Chart):
        chart = slide.shapes[0]
        recovered_workbook = chart.chart_data.chart_data_workbook

        # Read or modify the recovered workbook data here.
    else:
        print("The first shape is not a chart.")

If the external workbook is unavailable and recovery is disabled, Aspose.Slides raises an exception. Enable recovery only when using the cached chart data is an acceptable fallback, because the cache may not contain changes made to the external workbook after the presentation was last updated.

FAQ

Can I determine whether a specific chart is linked to an external or an embedded workbook?

Yes. A chart has a data source type and a path to an external workbook; if the source is an external workbook, you can read the full path to make sure an external file is being used.

Are relative paths to external workbooks supported, and how are they stored?

Yes. If you specify a relative path, it is automatically converted to an absolute path. The presentation stores the absolute path in the PPTX file, so moving the workbook may require updating the link.

Can I use workbooks located on network resources/shares?

Yes, such workbooks can be used as an external data source. However, editing remote workbooks directly from Aspose.Slides is not supported—they can only be used as a source.

Does Aspose.Slides overwrite the external XLSX when saving the presentation?

The presentation stores a link to the external file. Editing cell-backed chart data can also update the linked local XLSX file. Use a copy of the workbook if the original must remain unchanged.

What should I do if the external file is password-protected?

Aspose.Slides does not accept a password when linking. A common approach is to remove protection in advance or prepare a decrypted copy (for example, using Aspose.Cells) and link to that copy.

Can multiple charts reference the same external workbook?

Yes. Each chart stores its own link. If they all point to the same file, updating that file will be reflected in each chart the next time the data is loaded.

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