This repository consists of packages for use in Python Lab. This can contain any library we want to expose to students or any patches we want to apply to student code. Here are the current packages:
This package contains the python neighborhood package used in pythonlab. It is based on the javalab org.code.neighborhood package and includes the Painter class.
This package handles setup and teardown for Python Lab. For setup, it patches libraries for use in Python Lab. The current patches are:
- We patch
matplotlibin order to display graphs correctly. The patch updates theshowmethod to send a base64 encoded string for display in Python Lab. - We patch
requestsin order to route requests through code.org's request proxy. This protects students by only allowing requests to an allow-list of urls.
We run setup_pythonlab(), a method this package exposes, before each student run, which only applies
the matplotlib patch for now. We also run teardown_pythonlab() after each run, which flushes stdout and
changes directory to the home folder.
This tests adds some customization to the output of unit tests, and has a function to either run validation tests (more customized) or student tests (less customized).
This package contains the python theater package used in pythonlab. It is based on the Java Lab org.code.theater package and includes the Scene class and play_scenes function. A scene records drawing and audio commands; play_scenes renders them into an animated gif (via Pillow) and a WAV audio track (via numpy and the stdlib wave module) and returns the raw bytes. Instrument note samples and the Liberation fonts used for text are bundled as package data and read via importlib.resources, since network fetch is unavailable under Pyodide's jsglobals: {}.
The instrument notes are stored as headerless 8-bit mu-law at 22.05 kHz rather than as WAV files, and theater/support/instrument_samples.py decodes them back to the output rate on load. The theater wheel is pulled on every Python Lab page load, not just on theater levels, so minimizing the size is important.
play_scenes also hands both to the host for playback, through theater/support/bridge.py. That calls _theater_bridge.publish(gif_bytes, wav_bytes), a JS module the Pyodide web worker registers — the only route out of the interpreter under jsglobals: {}. wav_bytes is None for a program that made no sound, which the host reads as "no audio to wait on". In any other interpreter the module is absent and publishing is a no-op, which is what lets the tests render gifs without a browser.
From the package folder containing pyproject.toml, run uv build. The generated .whl file will be in the code-dot-org/dist folder.
The generated .whl file can then be copied to apps/lib/pyodide.
From CI run uv build automatically when folder content changes, and copy the resulting .whl to apps/lib/pyodide.
From the folder containing code and tests, run uv run pytest. This will look for tests in all files that start with test in the tests/ sub-directory.