Format Presentation Charts in Python

What this page is about

Learn chart formatting in Aspose.Slides for Python via Java and elevate your PowerPoint presentation with professional, eye-catching styling.

Overview

This article explains how to format charts in PowerPoint presentations by using Aspose.Slides. It shows how to customize key chart elements such as axes, grid lines, titles, legends, the plot area, and wall fills to improve the appearance and readability of chart data.

It also demonstrates how to set font properties for chart text, apply preset and custom numeric formats to chart data, and enable rounded corners for the chart area. Together, these examples show how to control both the visual style and data presentation of charts in a presentation.

Format Chart Entities

Aspose.Slides for Python via Java lets developers add custom charts to their slides from scratch. This article explains how to format different chart entities including the category and value axes.

Aspose.Slides for Python via Java provides a simple API for managing different chart entities and formatting them using custom values:

1. Create an instance of the Presentation class.
2. Access a slide by its index.
3. Add a chart of the desired type with default data (this example uses ChartType.LineWithMarkers).
4. Access the chart value axis and set the following properties:
   1. Set Line format for value axis major grid lines.
   2. Set Line format for value axis minor grid lines.
   3. Set Number Format for the value axis.
   4. Set minimum, maximum, major, and minor units for the value axis.
   5. Set Text Properties for the value axis data.
   6. Set Title for the value axis.
5. Access the chart category axis and set the following properties:
   1. Set Line format for category axis major grid lines.
   2. Set Line format for category axis minor grid lines.
   3. Set Text Properties for the category axis data.
   4. Set Title for the category axis.
   5. Set Label Positioning for the category axis.
   6. Set Rotation Angle for the category axis labels.
6. Access the chart legend and set its text properties.
7. Show the chart legend without overlapping the chart.
8. Access the chart secondary value axis and set the following properties:
   1. Enable the secondary value axis.
   2. Set Line Format for the secondary value axis.
   3. Set Number Format for the secondary value axis.
   4. Set minimum, maximum, major, and minor units for the secondary value axis.
9. Plot the first chart series on the secondary value axis.
10. Set the chart back wall fill color.
11. Set the chart plot area fill color.
12. Write the modified presentation to a PPTX file.

import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import ChartType, DisplayUnitType, FillType, FontData, LineDashStyle, LineStyle, NullableBool, Presentation, PresetColor, SaveFormat, TickLabelPositionType

Color = jpype.JClass("java.awt.Color")
nullable_true = NullableBool.True_

# Create an instance of the Presentation class
presentation = Presentation()
try:
    # Access the first slide
    slide = presentation.getSlides().get_Item(0)

    # Add the sample chart
    chart = slide.getShapes().addChart(ChartType.LineWithMarkers, 50, 50, 500, 400)

    # Set Chart Title
    chart.setTitle(True)
    chart.getChartTitle().addTextFrameForOverriding("")
    chart_title = chart.getChartTitle().getTextFrameForOverriding().getParagraphs().get_Item(0).getPortions().get_Item(0)
    chart_title.setText("Sample Chart")
    chart_title.getPortionFormat().getFillFormat().setFillType(FillType.Solid)
    chart_title.getPortionFormat().getFillFormat().getSolidFillColor().setColor(Color.GRAY)
    chart_title.getPortionFormat().setFontHeight(20)
    chart_title.getPortionFormat().setFontBold(nullable_true)
    chart_title.getPortionFormat().setFontItalic(nullable_true)

    # Set Major grid lines format for value axis
    chart.getAxes().getVerticalAxis().getMajorGridLinesFormat().getLine().getFillFormat().setFillType(FillType.Solid)
    chart.getAxes().getVerticalAxis().getMajorGridLinesFormat().getLine().getFillFormat().getSolidFillColor().setColor(Color.BLUE)
    chart.getAxes().getVerticalAxis().getMajorGridLinesFormat().getLine().setWidth(5)
    chart.getAxes().getVerticalAxis().getMajorGridLinesFormat().getLine().setDashStyle(LineDashStyle.DashDot)

    # Set Minor grid lines format for value axis
    chart.getAxes().getVerticalAxis().getMinorGridLinesFormat().getLine().getFillFormat().setFillType(FillType.Solid)
    chart.getAxes().getVerticalAxis().getMinorGridLinesFormat().getLine().getFillFormat().getSolidFillColor().setColor(Color.RED)
    chart.getAxes().getVerticalAxis().getMinorGridLinesFormat().getLine().setWidth(3)

    # Set value axis number format
    chart.getAxes().getVerticalAxis().setNumberFormatLinkedToSource(False)
    chart.getAxes().getVerticalAxis().setDisplayUnit(DisplayUnitType.Thousands)
    chart.getAxes().getVerticalAxis().setNumberFormat("0.0%")

    # Set chart maximum, minimum values
    chart.getAxes().getVerticalAxis().setAutomaticMajorUnit(False)
    chart.getAxes().getVerticalAxis().setAutomaticMaxValue(False)
    chart.getAxes().getVerticalAxis().setAutomaticMinorUnit(False)
    chart.getAxes().getVerticalAxis().setAutomaticMinValue(False)

    chart.getAxes().getVerticalAxis().setMaxValue(15)
    chart.getAxes().getVerticalAxis().setMinValue(-2)
    chart.getAxes().getVerticalAxis().setMinorUnit(0.5)
    chart.getAxes().getVerticalAxis().setMajorUnit(2.0)

    # Set Value Axis Text Properties
    value_axis_text = chart.getAxes().getVerticalAxis().getTextFormat().getPortionFormat()
    value_axis_text.setFontBold(nullable_true)
    value_axis_text.setFontHeight(16)
    value_axis_text.setFontItalic(nullable_true)
    value_axis_text.getFillFormat().setFillType(FillType.Solid)
    value_axis_text.getFillFormat().getSolidFillColor().setPresetColor(PresetColor.DarkGreen)
    value_axis_font = FontData("Times New Roman")
    value_axis_text.setLatinFont(value_axis_font)

    # Set value axis title
    chart.getAxes().getVerticalAxis().setTitle(True)
    chart.getAxes().getVerticalAxis().getTitle().addTextFrameForOverriding("")
    value_axis_title = chart.getAxes().getVerticalAxis().getTitle().getTextFrameForOverriding().getParagraphs().get_Item(0).getPortions().get_Item(0)
    value_axis_title.setText("Primary Axis")
    value_axis_title.getPortionFormat().getFillFormat().setFillType(FillType.Solid)
    value_axis_title.getPortionFormat().getFillFormat().getSolidFillColor().setColor(Color.GRAY)
    value_axis_title.getPortionFormat().setFontHeight(20)
    value_axis_title.getPortionFormat().setFontBold(nullable_true)
    value_axis_title.getPortionFormat().setFontItalic(nullable_true)

    # Set Major grid lines format for Category axis
    chart.getAxes().getHorizontalAxis().getMajorGridLinesFormat().getLine().getFillFormat().setFillType(FillType.Solid)
    chart.getAxes().getHorizontalAxis().getMajorGridLinesFormat().getLine().getFillFormat().getSolidFillColor().setColor(Color.GREEN)
    chart.getAxes().getHorizontalAxis().getMajorGridLinesFormat().getLine().setWidth(5)

    # Set Minor grid lines format for Category axis
    chart.getAxes().getHorizontalAxis().getMinorGridLinesFormat().getLine().getFillFormat().setFillType(FillType.Solid)
    chart.getAxes().getHorizontalAxis().getMinorGridLinesFormat().getLine().getFillFormat().getSolidFillColor().setColor(Color.YELLOW)
    chart.getAxes().getHorizontalAxis().getMinorGridLinesFormat().getLine().setWidth(3)

    # Set Category Axis Text Properties
    category_axis_text = chart.getAxes().getHorizontalAxis().getTextFormat().getPortionFormat()
    category_axis_text.setFontBold(nullable_true)
    category_axis_text.setFontHeight(16)
    category_axis_text.setFontItalic(nullable_true)
    category_axis_text.getFillFormat().setFillType(FillType.Solid)
    category_axis_text.getFillFormat().getSolidFillColor().setColor(Color.BLUE)
    category_axis_font = FontData("Arial")
    category_axis_text.setLatinFont(category_axis_font)

    # Set Category Title
    chart.getAxes().getHorizontalAxis().setTitle(True)
    chart.getAxes().getHorizontalAxis().getTitle().addTextFrameForOverriding("")

    category_axis_title = chart.getAxes().getHorizontalAxis().getTitle().getTextFrameForOverriding().getParagraphs().get_Item(0).getPortions().get_Item(0)
    category_axis_title.setText("Sample Category")
    category_axis_title.getPortionFormat().getFillFormat().setFillType(FillType.Solid)
    category_axis_title.getPortionFormat().getFillFormat().getSolidFillColor().setColor(Color.GRAY)
    category_axis_title.getPortionFormat().setFontHeight(20)
    category_axis_title.getPortionFormat().setFontBold(nullable_true)
    category_axis_title.getPortionFormat().setFontItalic(nullable_true)

    # Set category axis label position
    chart.getAxes().getHorizontalAxis().setTickLabelPosition(TickLabelPositionType.Low)

    # Set category axis label rotation angle
    chart.getAxes().getHorizontalAxis().setTickLabelRotationAngle(45)

    # Set Legends Text Properties
    legend_text = chart.getLegend().getTextFormat().getPortionFormat()
    legend_text.setFontBold(nullable_true)
    legend_text.setFontHeight(16)
    legend_text.setFontItalic(nullable_true)
    legend_text.getFillFormat().setFillType(FillType.Solid)
    legend_text.getFillFormat().getSolidFillColor().setPresetColor(PresetColor.DarkRed)

    # Show the chart legend without overlapping the chart

    chart.getLegend().setOverlay(False)

    chart.getChartData().getSeries().get_Item(0).setPlotOnSecondAxis(True)
    # Set secondary value axis
    chart.getAxes().getSecondaryVerticalAxis().setVisible(True)
    chart.getAxes().getSecondaryVerticalAxis().getFormat().getLine().setStyle(LineStyle.ThickBetweenThin)
    chart.getAxes().getSecondaryVerticalAxis().getFormat().getLine().setWidth(20)

    # Set secondary value axis Number format
    chart.getAxes().getSecondaryVerticalAxis().setNumberFormatLinkedToSource(False)
    chart.getAxes().getSecondaryVerticalAxis().setDisplayUnit(DisplayUnitType.Hundreds)
    chart.getAxes().getSecondaryVerticalAxis().setNumberFormat("0.0%")

    # Set chart maximum, minimum values
    chart.getAxes().getSecondaryVerticalAxis().setAutomaticMajorUnit(False)
    chart.getAxes().getSecondaryVerticalAxis().setAutomaticMaxValue(False)
    chart.getAxes().getSecondaryVerticalAxis().setAutomaticMinorUnit(False)
    chart.getAxes().getSecondaryVerticalAxis().setAutomaticMinValue(False)

    chart.getAxes().getSecondaryVerticalAxis().setMaxValue(20)
    chart.getAxes().getSecondaryVerticalAxis().setMinValue(-5)
    chart.getAxes().getSecondaryVerticalAxis().setMinorUnit(0.5)
    chart.getAxes().getSecondaryVerticalAxis().setMajorUnit(2.0)

    # Set chart back wall color
    chart.getBackWall().setThickness(1)
    chart.getBackWall().getFormat().getFill().setFillType(FillType.Solid)
    chart.getBackWall().getFormat().getFill().getSolidFillColor().setColor(Color.ORANGE)

    chart.getFloor().getFormat().getFill().setFillType(FillType.Solid)
    chart.getFloor().getFormat().getFill().getSolidFillColor().setColor(Color.RED)
    # Set Plot area color
    chart.getPlotArea().getFormat().getFill().setFillType(FillType.Solid)
    chart.getPlotArea().getFormat().getFill().getSolidFillColor().setPresetColor(PresetColor.LightCyan)

    # Save the presentation
    presentation.save("FormattedChart.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()

Set Font Properties for a Chart

Aspose.Slides for Python via Java supports setting font properties for charts. Follow these steps to set the font properties:

• Create an instance of the Presentation class.
• Add a chart to the slide.
• Set font height.
• Save the modified presentation.

The following example demonstrates these steps.

import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import ChartType, Presentation, SaveFormat

# Create an instance of the Presentation class
presentation = Presentation()
try:
    chart = presentation.getSlides().get_Item(0).getShapes().addChart(ChartType.ClusteredColumn, 100, 100, 500, 400)

    chart.getTextFormat().getPortionFormat().setFontHeight(20)
    chart.getChartData().getSeries().get_Item(0).getLabels().getDefaultDataLabelFormat().setShowValue(True)

    presentation.save("FontPropertiesForChart.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()

Set the Numeric Format

Aspose.Slides for Python via Java provides a simple API for managing chart data formats:

1. Create an instance of the Presentation class.
2. Access a slide by its index.
3. Add a chart of the desired type with default data (this example uses ChartType.ClusteredColumn).
4. Set the preset number format from the possible preset values.
5. Iterate through the data cells in every chart series and set their number format.
6. Save the presentation.

import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import ChartType, Presentation, SaveFormat

# Create an instance of the Presentation class
presentation = Presentation()
try:
    # Access the first presentation slide
    slide = presentation.getSlides().get_Item(0)

    # Add a default clustered column chart
    chart = slide.getShapes().addChart(ChartType.ClusteredColumn, 50, 50, 500, 400)

    # Access the chart series collection
    chart_series_collection = chart.getChartData().getSeries()

    # Iterate through every chart series
    for chart_series in chart_series_collection:
        # Iterate through every data point in the series
        for data_point in chart_series.getDataPoints():
            # Set the number format
            data_point.getValue().getAsCell().setPresetNumberFormat(jpype.JByte(10))  # 0.00%

    # Save the presentation
    presentation.save("PresetNumberFormat.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()

The available preset number formats and their indices are listed below:

0	General
1	0
2	0.00
3	#,##0
4	#,##0.00
5	$#,##0;$-#,##0
6	$#,##0;Red$-#,##0
7	$#,##0.00;$-#,##0.00
8	$#,##0.00;Red$-#,##0.00
9	0%
10	0.00%
11	0.00E+00
12	# ?/?
13	# /
14	m/d/yy
15	d-mmm-yy
16	d-mmm
17	mmm-yy
18	h:mm AM/PM
19	h:mm:ss AM/PM
20	h:mm
21	h:mm:ss
22	m/d/yy h:mm
37	#,##0;-#,##0
38	#,##0;Red-#,##0
39	#,##0.00;-#,##0.00
40	#,##0.00;Red-#,##0.00
41	_ * #,##0_ ;_ * “_ ;_ @_
42	_ $* #,##0_ ;_ $* “_ ;_ @_
43	_ * #,##0.00_ ;_ * “??_ ;_ @_
44	_ $* #,##0.00_ ;_ $* “??_ ;_ @_
45	mm:ss
46	h:mm:ss
47	mm:ss.0
48	##0.0E+00
49	@

Set Chart Area Rounded Borders

Aspose.Slides for Python via Java supports rounded corners for the chart area through the hasRoundedCorners and setRoundedCorners methods of the Chart class.

1. Create an instance of the Presentation class.
2. Add a chart to the slide.
3. Set the fill type and style of the chart border line.
4. Enable rounded corners.
5. Save the modified presentation.

The following example demonstrates these steps.

import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import ChartType, FillType, LineStyle, Presentation, SaveFormat

# Create an instance of the Presentation class
presentation = Presentation()
try:
    slide = presentation.getSlides().get_Item(0)

    chart = slide.getShapes().addChart(ChartType.ClusteredColumn, 20, 100, 600, 400)
    chart.getLineFormat().getFillFormat().setFillType(FillType.Solid)
    chart.getLineFormat().setStyle(LineStyle.Single)
    chart.setRoundedCorners(True)

    presentation.save("output.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()

FAQ

Can I set semi-transparent fills for columns/areas while keeping the border opaque?

Yes. Fill transparency and the outline are configured separately. This is useful for improving the readability of the grid and data in dense visualizations.

How can I deal with data labels when they overlap?

Reduce the font size, disable nonessential label components (for example, categories), set the label offset/position, show labels only for selected points if necessary, or switch the format to “value + legend”.

Can I apply gradient or pattern fills to series?

Yes. Both solid and gradient/pattern fills are typically available. In practice, use gradients sparingly and avoid combinations that reduce contrast with the grid and text.