Update text in an existing PowerPoint deck with Python

Replace a placeholder and keep its formatting

from wolfppt import Presentation

prs = Presentation("monthly_review.pptx")
for slide in prs.slides:
    for shape in slide.shapes:
        if not shape.has_text_frame:
            continue
        for paragraph in shape.text_frame.paragraphs:
            for run in paragraph.runs:
                if "{{month}}" in run.text:
                    run.text = run.text.replace("{{month}}", "September")
prs.save("monthly_review_updated.pptx")

Assigning to run.textkeeps that run's font, size, color, and bold settings. The saved copy changes the edited slide XML only; masters, layouts, media, charts, and notes you did not touch keep their original bytes.

When to use WolfPPT and when to use python-pptx

• Use WolfPPT when a recurring deck already exists and a pipeline should change approved text inside it while the rest of the file stays as it was.
• Use python-pptx when you are generating a new deck from code, or when you need an API surface that the WolfPPT facade does not cover yet.
• The facade mirrors python-pptx names such as Presentation, slides, shapes, text_frame, and runs, so an existing edit script usually needs only its import changed. Check the compatibility matrix for each call you rely on.

Limitations

• A placeholder split across several runs appears as separate run texts; the loop above matches a placeholder only when one run holds all of it.
• Setting shape.text rewrites the whole text body as newline-separated paragraphs. Use run-level assignment when formatting inside the shape must stay intact.
• The facade covers a documented subset of python-pptx, and mutation guards refuse unsafe edits instead of writing them.

Review the WolfPPT compatibility matrix

Install WolfPPT

The public WolfPPT release is MIT-licensed and free, including commercial use.

pip install wolfppt

PyPI wheels cover CPython 3.11 to 3.14 on Linux x86_64 and aarch64 and on macOS arm64. Source, tests, and the full facade reference live at github.com/wolfiesch/wolfppt-oss.

Related tasks

• Update text in an existing PowerPoint deck with Python
• Update a table in an existing PowerPoint deck with Python
• Update chart data in an existing PowerPoint deck with Python