PPTX Debugging Workflow

A systematic approach to creating and debugging PowerPoint presentations using the

python-pptx

Step 1: Verify Installation

Before writing any code, verify that

python-pptx

pip show python-pptx

If not installed:

pip install python-pptx

Step 2: Test Minimal PPTX Creation

Create and run a minimal test script to verify the library works:

from pptx import Presentation

prs = Presentation()
slide = prs.slides.add_slide(prs.slide_layouts[0])
slide.shapes.title.text = "Test Slide"
prs.save("test.pptx")
print("Test presentation created successfully")

Run this first to confirm basic functionality before building complex presentations.

Step 3: Write Full Script to File

Always write your presentation script to a

.py

• Better error messages with line numbers
• Easier iteration and debugging
• Preserved state between error fixes

Example structure:

from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.enum.shapes import MSO_SHAPE
from pptx.enum.chart import XL_CHART_TYPE, XL_LEGEND_POSITION
from pptx.chart.data import CategoryChartData

def create_presentation():
    prs = Presentation()
    # Build slides here
    prs.save("output.pptx")
    print("Presentation saved successfully")

if __name__ == "__main__":
    create_presentation()

Step 4: Execute and Capture Full Traceback

Run the script with full error output:

python your_script.py 2>&1 | tee debug_output.log

This captures the complete Python traceback including:

• Error type and message
• Line numbers where errors occurred
• Stack trace for debugging

Step 5: Fix API Errors Iteratively

Common

python-pptx

Chart Legend Positioning

Use

XL_LEGEND_POSITION

XL_CHART_TYPE

from pptx.enum.chart import XL_LEGEND_POSITION

chart.chart.has_legend = True
chart.chart.legend.position = XL_LEGEND_POSITION.RIGHT

Table Cell Access

Access table cells through row iteration pattern:

table = slide.shapes.add_table(rows=5, cols=4, left=Inches(1), top=Inches(2), width=Inches(6), height=Inches(3)).table

# Correct pattern - iterate through rows, then cells
for row_idx, row in enumerate(table.rows):
    for cell_idx, cell in enumerate(row.cells):
        cell.text = f"Row {row_idx}, Cell {cell_idx}"

# Or direct access
table.rows[0].cells[0].text = "Header"

Chart Data Format

For pie charts, use category-based data:

chart_data = CategoryChartData()
chart_data.categories = ['Category A', 'Category B', 'Category C']
chart_data.add_series('Series 1', (30, 45, 25))

x, y, cx, cy = Inches(2), Inches(2), Inches(6), Inches(4.5)
slide.shapes.add_chart(XL_CHART_TYPE.PIE, x, y, cx, cy, chart_data)

Step 6: Validate Output

After successful execution:

1. Verify the

   .pptx

   file was created
2. Open in PowerPoint or compatible viewer
3. Check that all slides, tables, and charts render correctly

Common Troubleshooting

pip install python-pptx

XL_LEGEND_POSITION

XL_CHART_TYPE

table.rows[row].cells[cell]

pptx.enum.*

Quick Reference Script Template

from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.enum.chart import XL_CHART_TYPE, XL_LEGEND_POSITION
from pptx.chart.data import CategoryChartData

def main():
    prs = Presentation()
    
    # Add title slide
    slide = prs.slides.add_slide(prs.slide_layouts[0])
    slide.shapes.title.text = "Title"
    
    # Add content slide with table
    slide = prs.slides.add_slide(prs.slide_layouts[1])
    table = slide.shapes.add_table(3, 3, Inches(1), Inches(2), Inches(8), Inches(2)).table
    for row in table.rows:
        for cell in row.cells:
            cell.text = "Data"
    
    prs.save("presentation.pptx")
    print("Done!")

if __name__ == "__main__":
    main()