pptx-debug-workflow

PPTX Debugging Workflow

A systematic approach to creating and debugging PowerPoint presentations using the python-pptx library. This workflow ensures reliable presentation generation through iterative verification and error resolution.

Step 1: Verify Installation

Before writing any code, verify that python-pptx is installed:

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 file instead of using heredoc or inline execution. This enables:

• 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 API patterns to remember:

Chart Legend Positioning

Use XL_LEGEND_POSITION (NOT XL_CHART_TYPE) for legend positioning:

from pptx.enum.chart import XL_LEGEND_POSITION

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