Python Android Support

This is a meta-package for building a version of CPython that can be embedded into an Android project. It supports Python versions 3.7 through 3.11 (inclusive).

It works by downloading, patching, and building CPython and selected pre- requisites, packaging them as linkable dynamic libraries, and packaging that into a ZIP file. It builds binaries for all four major Android ABIs.

Quickstart

The easiest way to use this support package is to use briefcase. Briefcase uses a pre-compiled version of the support package to build complete Android applications. See Briefcase's documentation for more details.

Pre-built versions of the frameworks can be downloaded and added to your project. See this documentation for more details on how to build an Android project using this support package.

Alternatively, to build the frameworks on your own, download/clone this repository, and then in the root directory, and run ./main.sh to build everything. You will need Docker installed; all other requirements will be downloaded as part of the installation script.

This should:

1. Download the original source packages
2. Patch them as required for compatibility with the selected OS
3. Build the packages.

The build products will be in the build directory; the compiled artefacts will be in the dist directory.

You can then follow these same instructions for building an Android application.

Testing

When you do a local build, you can use the support_package = ... configuration option in a briefcase app's pyproject.toml to point the app at your local support library.

You can run python3 test_all_extensions_built.py dist/Python-*-Android-support.custom.zip to quickly validate that the expected compiled extension modules are available for a given build.

To run the CPython test suite within an app context, you can add this code to a briefcase app:

import os, sys
sys.executable = sys.prefix + "/bin/" + sorted([x for x in os.listdir(sys.prefix + "/bin/") if x.startswith("python3.")])[0]
os.chmod(sys.executable, 0o755)
from test.libregrtest import main
result = None
try:
    result = main([], use_resources=['network'])
except SystemExit as e:
    # Do not let SystemExit bubble up further; if the app exits with a nonzero
    # status code, Android restarts it, which is rather annoying. :)
    print('Would exit with statuscode', e.code)
else:
    print("Tests finished with result", result)

Note that you must modify the pythonhome excludes list for this to work properly, which will make the support package larger.