# name: processing-pptx description: Creates, reads, and modifies PowerPoint presentations (.pptx, .potx) with python-pptx — slides, layouts, text, tables, images, charts. Use when the user asks to create, build, read, edit, or fix a presentation, deck, or slides, or mentions .pptx/.potx files or PowerPoint. Do not use for Word documents, PDFs, or Google Slides.

# Processing PPTX

# When to use / when NOT to use

• Use for: creating, reading, or modifying .pptx and .potx files — slides, text, tables, images, charts, speaker notes.
• Do NOT use for: Word documents, PDFs, or Google Slides (different API).

# Quick reference

Default library: python-pptx. Visual verification: LibreOffice render to PDF/images when layout correctness matters.

Create:

from pptx import Presentation
from pptx.util import Inches, Pt

prs = Presentation()                      # 4:3 default; set 16:9 explicitly:
prs.slide_width, prs.slide_height = Inches(13.333), Inches(7.5)

slide = prs.slides.add_slide(prs.slide_layouts[0])   # 0 = title slide
slide.shapes.title.text = "Q3 Results"
slide.placeholders[1].text = "Finance Team — 2026"
prs.save("deck.pptx")

Read:

from pptx import Presentation
for i, slide in enumerate(Presentation("deck.pptx").slides, 1):
    for shape in slide.shapes:
        if shape.has_text_frame:
            print(i, shape.text_frame.text)

Modify:

prs = Presentation("deck.pptx")
slide = prs.slides[1]
for shape in slide.shapes:
    if shape.has_text_frame and "draft" in shape.text_frame.text.lower():
        shape.text_frame.text = shape.text_frame.text.replace("Draft", "Final")
prs.save("deck.pptx")

Visual check (when layout matters):

soffice --headless --convert-to pdf deck.pptx   # then inspect pages for overflow/overlap

# Design rules

• Safe fonts only: Arial or Calibri.
• Keep ≥0.5" margins; body text ≥14pt, titles ≥28pt.
• No text-only slides in a finished deck — add an image, chart, or table per slide where content allows.
• Build a new deck from an existing template (Presentation("template.potx")) when the user has one; reuse its layouts instead of drawing boxes manually.

# Workflow

1. Classify the task: create / read / modify.
2. Creating: start from the user's template if provided, else default template with 16:9 size. Use slide layouts and placeholders, not free-floating text boxes, so themes apply.
3. Modifying: read all slides first; edit in place, preserving each shape's position and formatting.
4. Validate: re-open with Presentation(path) — if it raises, fix before delivering. Count slides and confirm expected titles.
5. If the deck is a final deliverable, render via soffice --headless --convert-to pdf and check for text overflow, overlap, and contrast.
6. Report the output path, slide count, and what changed.

# Edge cases & failure modes

• python-pptx missing → pip install python-pptx. LibreOffice missing → brew install --cask libreoffice (only needed for visual checks/conversion).
• Corrupt / not a zip → Presentation() raises PackageNotFoundError; report invalid pptx, stop.
• Password-protected file → python-pptx cannot decrypt; ask for an unprotected copy.
• .ppt (legacy binary) → unsupported; convert first: soffice --headless --convert-to pptx file.ppt.
• Text overflowing its box → python-pptx cannot measure rendered text; shorten text or reduce font size, then re-render to verify.

# References

Deeper recipes (bullets, tables, images, charts, speaker notes, template reuse, per-slide deletion, conversion, gotchas): see references/recipes.md.