powerpoint

Overview

Create, read, and edit PowerPoint (.pptx) files programmatically using the python-pptx library. Handles slide creation, text formatting, images, tables, charts, shapes, slide layouts, and speaker notes. Works without PowerPoint installed — reads and writes the Open XML format directly.

Instructions

Setup

pip install python-pptx

Alternative — AI-generated PPTX: For fully automated slide generation from text prompts, Presenton (github.com/presenton/presenton) is an open-source tool that produces PPTX using OpenAI, Gemini, Claude, or Ollama. Runs locally via Docker. Use python-pptx (below) when you need precise control over content, formatting, and programmatic data-driven generation.

Object model

Presentation
├── slide_layouts[]    # Layout variants (title, content, blank, etc.)
├── slides[]           # Actual slides
│   ├── shapes[]       # Text boxes, images, charts, tables
│   │   ├── text_frame → paragraphs[] → runs[]  # Text with formatting
│   │   └── table      # Table object (if table shape)
│   └── notes_slide    # Speaker notes
└── core_properties    # Title, author, subject

Layout indices vary by template. Always verify first:

for i, layout in enumerate(prs.slide_layouts):
    print(i, layout.name)

Common defaults: 0 = Title Slide, 1 = Title and Content, 5 = Title Only, 6 = Blank.

Creating a presentation

from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN

prs = Presentation()

# Title slide
slide = prs.slides.add_slide(prs.slide_layouts[0])
slide.shapes.title.text = "Q4 Revenue Report"
slide.placeholders[1].text = "Finance Team — January 2025"

# Content slide with bullets
slide = prs.slides.add_slide(prs.slide_layouts[1])
slide.shapes.title.text = "Key Highlights"
tf = slide.placeholders[1].text_frame
tf.text = "Revenue up 23% year-over-year"
p = tf.add_paragraph()
p.text = "New enterprise clients: 14"
p.level = 1

prs.save("report.pptx")

Editing existing files (template fill)

prs = Presentation("template.pptx")
for slide in prs.slides:
    for shape in slide.shapes:
        if shape.has_text_frame:
            for paragraph in shape.text_frame.paragraphs:
                for run in paragraph.runs:
                    if "{{COMPANY}}" in run.text:
                        run.text = run.text.replace("{{COMPANY}}", "Acme Corp")
prs.save("filled.pptx")

Quick reference — adding elements

Image:

slide.shapes.add_picture("photo.png", Inches(1), Inches(1.5), width=Inches(8))

Table:

tbl = slide.shapes.add_table(rows, cols, Inches(1), Inches(2), Inches(8), Inches(3)).table
tbl.cell(0, 0).text = "Header"

Chart:

from pptx.chart.data import CategoryChartData
from pptx.enum.chart import XL_CHART_TYPE

chart_data = CategoryChartData()
chart_data.categories = ["Q1", "Q2", "Q3", "Q4"]
chart_data.add_series("Revenue", (3.2, 3.8, 4.2, 5.1))
slide.shapes.add_chart(XL_CHART_TYPE.COLUMN_CLUSTERED, Inches(1), Inches(2), Inches(8), Inches(4.5), chart_data)

Speaker notes:

slide.notes_slide.notes_text_frame.text = "Key talking point here."

Text formatting:

run = paragraph.runs[0]
run.font.size = Pt(28)
run.font.bold = True
run.font.color.rgb = RGBColor(0x1A, 0x73, 0xE8)
run.font.name = "Calibri"
paragraph.alignment = PP_ALIGN.CENTER

Design principles for generated slides

Apply these rules when building presentations programmatically:

Typography: Use Inter, Poppins, or Montserrat instead of default Calibri. One font family per presentation. Titles minimum 36pt, body minimum 24pt. Set line spacing to 1.2–1.3 for body text, 0.8–0.9 for large display text.

Layout: Left-align body text (center only for short titles). Use generous margins — Inches(1) minimum on all sides. Use multi-column layouts for readability. Vary slide designs while keeping a consistent style.

Content density: One idea per slide. Maximum 6 lines of text, 6 words per line. Split dense content across multiple slides (~30 seconds each). Replace bullet lists with visual hierarchy using font size, weight, and spacing.

Whitespace: Treat empty space as a design element, not wasted space. Apply padding inside boxes and shapes — at least Inches(0.3) internal margin.

Visuals: One hero image or chart per slide. Use high-contrast text on backgrounds. SVG icons from Noun Project (thenounproject.com) enhance slides without clutter. For professional templates as starting points, download PPTX files from Slidesgo (slidesgo.com) and load them with Presentation("template.pptx").

Examples

Example 1: Generate a sales report from JSON data

User request: "Create a PowerPoint report from this sales data JSON file"

import json
from pptx import Presentation
from pptx.util import Inches
from pptx.chart.data import CategoryChartData
from pptx.enum.chart import XL_CHART_TYPE

with open("sales_data.json") as f:
    data = json.load(f)

prs = Presentation()

# Title slide
slide = prs.slides.add_slide(prs.slide_layouts[0])
slide.shapes.title.text = f"Sales Report — {data['period']}"
slide.placeholders[1].text = f"Generated {data['generated_date']}"

# Summary slide
slide = prs.slides.add_slide(prs.slide_layouts[1])
slide.shapes.title.text = "Executive Summary"
tf = slide.placeholders[1].text_frame
tf.text = f"Total Revenue: ${data['total_revenue']:,.0f}"
p = tf.add_paragraph()
p.text = f"Units Sold: {data['units_sold']:,}"
p = tf.add_paragraph()
p.text = f"Top Region: {data['top_region']}"

# Chart slide — revenue by region
chart_data = CategoryChartData()
chart_data.categories = [r["name"] for r in data["regions"]]
chart_data.add_series("Revenue ($M)", [r["revenue"] for r in data["regions"]])
slide = prs.slides.add_slide(prs.slide_layouts[5])
slide.shapes.title.text = "Revenue by Region"
slide.shapes.add_chart(
    XL_CHART_TYPE.COLUMN_CLUSTERED,
    Inches(1), Inches(2), Inches(8), Inches(4.5), chart_data
)

# Table slide — product breakdown
products = data["products"]
slide = prs.slides.add_slide(prs.slide_layouts[5])
slide.shapes.title.text = "Product Performance"
tbl = slide.shapes.add_table(len(products) + 1, 3, Inches(1), Inches(2), Inches(8), Inches(3)).table
for j, h in enumerate(["Product", "Units", "Revenue"]):
    tbl.cell(0, j).text = h
for i, prod in enumerate(products):
    tbl.cell(i + 1, 0).text = prod["name"]
    tbl.cell(i + 1, 1).text = f"{prod['units']:,}"
    tbl.cell(i + 1, 2).text = f"${prod['revenue']:,.0f}"

prs.save("sales_report.pptx")

Example 2: Batch-update branding across PPTX templates

User request: "Update the company name and logo across all our PPTX templates"

import glob
from pptx import Presentation
from pptx.util import Inches

old_name, new_name = "OldCorp Inc.", "NewBrand Technologies"
new_logo = "assets/newbrand_logo.png"

for filepath in glob.glob("templates/*.pptx"):
    prs = Presentation(filepath)
    for slide in prs.slides:
        to_remove = []
        for shape in slide.shapes:
            if shape.has_text_frame:
                for para in shape.text_frame.paragraphs:
                    for run in para.runs:
                        if old_name in run.text:
                            run.text = run.text.replace(old_name, new_name)
            if shape.shape_type == 13 and shape.name.startswith("Logo"):
                to_remove.append((shape, shape.left, shape.top, shape.width, shape.height))
                slide.shapes.add_picture(new_logo, shape.left, shape.top, shape.width, shape.height)
        for shape, *_ in to_remove:
            shape._element.getparent().remove(shape._element)

    output = filepath.replace("templates/", "updated/")
    prs.save(output)
    print(f"Updated: {output}")

Example 3: Extract presentation content to markdown

User request: "Extract all content from this PowerPoint into a markdown file"

from pptx import Presentation

prs = Presentation("presentation.pptx")
md_lines = [f"# {prs.core_properties.title or 'Presentation'}\n"]

for i, slide in enumerate(prs.slides):
    md_lines.append(f"\n## Slide {i + 1}")
    for shape in slide.shapes:
        if shape.has_text_frame:
            for para in shape.text_frame.paragraphs:
                text = para.text.strip()
                if not text:
                    continue
                if para.level == 0 and shape == slide.shapes.title:
                    md_lines.append(f"\n### {text}")
                else:
                    md_lines.append(f"{'  ' * para.level}- {text}")
    if slide.has_notes_slide:
        notes = slide.notes_slide.notes_text_frame.text.strip()
        if notes:
            md_lines.append(f"\n> **Notes:** {notes}")

with open("extracted.md", "w") as f:
    f.write("\n".join(md_lines))

Guidelines

• Always use from pptx.util import Inches, Pt for positioning — never raw EMU values unless doing precise math.
• When editing existing files, iterate paragraph.runs to preserve formatting. Setting text_frame.text directly destroys all existing font styles.
• Check available layouts with enumerate(prs.slide_layouts) before using hardcoded indices — they vary by template.
• For template-based generation, use placeholder shapes (slide.placeholders[idx]) rather than adding new shapes. This preserves the template's design.
• Start from professional templates (e.g., Slidesgo PPTX downloads) rather than blank presentations — the design quality will be significantly higher.
• python-pptx does not support animations, transitions, or embedded video. Create the base PPTX and instruct the user to add those in PowerPoint.
• When building tables, set column widths explicitly — auto-sizing is not supported and defaults produce uneven columns.
• Set font.name explicitly on every run when generating from scratch — default Calibri looks generic. Inter, Poppins, and Montserrat are free alternatives available via Google Fonts.
• Save to a new filename when editing to avoid corrupting the source file during development.