Pyodide Python compatibility

Python Standard library

Most of the Python standard library is functional, except for the modules listed in the sections below. A large part of the CPython test suite passes except for tests skipped in src/tests/python_tests.txt or via patches.

Optional modules

The following stdlib modules are included by default, however they can be excluded with loadPyodide({..., fullStdLib = false }). Individual modules can then be loaded as necessary using pyodide.loadPackage,

  • distutils

  • test: it is an exception to the above, since it is excluded by default.

Removed modules

The following modules are removed from the standard library to reduce download size and since they currently wouldn’t work in the WebAssembly VM,

  • curses

  • dbm

  • ensurepip

  • idlelib

  • lib2to3

  • tkinter


  • turtledemo

  • venv

  • pwd

Included but not working modules

The following modules can be imported, but are not functional due to the limitations of the WebAssembly VM:

  • multiprocessing

  • threading

  • sockets

as well as any functionality that requires these.