Slyde

Slyde is a native wxPython slideshow for editable Python percent notebooks. A slide is introduced by a # %% Title [slide] marker. Python and markdown cells after it belong to that slide until another slide marker appears.

Set up

Install uv and sync the project:

uv sync

On Linux, wxPython may need system GTK and WebKit development/runtime packages. Markdown uses wx.html2.WebView when available and falls back to wx.html.HtmlWindow.

Launch

uv run slyde
uv run slyde examples/interactive.py
uv run slyde examples/animation.py

examples/animation.py builds a square wave out of sine harmonics and uses each of the animate settings described below.

Cells run in the directory Slyde was launched from, so relative paths in a notebook resolve against it.

Without a path, use File → Open. A notebook with PEP 723 inline metadata is started through uv run --with for each declared dependency; its packages are made available in the GUI process, so code and embedded Matplotlib widgets share the notebook's environment. uv must be installed and available on PATH. When opening such a notebook from the file picker, Slyde starts a new app process under uv and closes the current window. This first run may resolve and download packages.

The example declares its packages at the top of the notebook:

# /// script
# requires-python = ">=3.11"
# dependencies = ["matplotlib", "numpy"]
# ///

Inline requirements are resolved by uv on demand. No adjacent lockfile is created automatically; add version bounds to dependency strings when a notebook needs tighter version constraints.

Notebook format

# /// script
# requires-python = ">=3.11"
# dependencies = ["matplotlib", "numpy"]
# ///

# %% Introduction [slide]
# %% [markdown]
# Use markdown cells to explain the idea.

# %% [slide]
# %% [markdown]
# Slides may contain more than one cell.

# %% Build a plot
import matplotlib.pyplot as plt

Supported cell types are Python (the default) and [markdown]. [slide] starts a new slide; text before the type marker is its optional title. Marker lines and the preamble are retained when saving. Only Python cells are editable in the UI.

Maths between dollar signs in a markdown cell is rendered as equations: $a^2 + b^2$ within a line, and $$ ... $$ on its own.

A marker may carry key="value" options after its type. [slide] takes animate:

# %% Results [slide] animate="bullet"

• none shows the whole slide at once, and is the default.
• paragraph reveals each top-level markdown block and each code cell one at a time.
• bullet does the same, and also reveals list items one at a time.

Controls

• Shift+Enter runs the focused Python cell.
• The Kernel menu runs several cells at once or starts over:
  • Run All Cells (Cmd+Shift+A) runs every Python cell in the notebook.
  • Run Until Current Slide (Cmd+Shift+U) runs the Python cells on the slides before the current one.
  • Restart Kernel & Clear All Cells (Cmd+Shift+R) discards the shared namespace and every cell's output, after asking for confirmation.
• Left/Up and Right/Down change slides when focus is outside a code editor, and step through the content of an animated slide before moving on; Cmd+Left/Up and Cmd+Right/Down work even while editing a cell (the platform command key is Ctrl on Windows/Linux).
• Cmd+plus and Cmd+minus scale slide content between 50% and 200% (the platform command key is Ctrl on Windows/Linux).
• F11 toggles full screen; Escape exits full screen.
• View → Slide Size sets the window so the slide gets exactly the room a projector would, for rehearsing a deck at the size it will be shown.
• Ctrl+S saves edits to the source .py file.

Python cells run in a shared namespace in the GUI process, one at a time. Printed output and exceptions appear below the cell, and long lines scroll horizontally instead of wrapping. Matplotlib figures created by a cell are embedded as interactive wx canvases with the standard toolbar for home, back/forward, pan, zoom, and save. A code cell is as tall as its source, and the plot beside it takes the size Matplotlib needs for it. A plot shrinks by up to 30% when that makes the slide fit the window; otherwise it stays full size and the slide scrolls. Output appears as it is produced, and the window stays usable while a cell runs. A queued run from the Kernel menu shows its progress in a strip at the bottom of the window, and stops at the first cell that raises, moving to that slide.