This repo contains the source code of Python 2.7.18 customized to compile with Cosmopolitan libc. Meant for experimental purposes only.

The header_stubs folder contains dummy headers corresponding to the C stdlib. The libcosmo folder should contain the required files for compiling an executable using Cosmopolitan on Linux.

The compiled APE runs on Linux and Windows -- the Python standard library, platform dependent files, pip, and setuptools are all contained within the executable, (APEs are also valid ZIP files!!!). Note: environment variables PYTHONPATH and PYTHONHOME are NOT read during interpreter startup.

The following modules of the Python stdlib are currently not compiled:

_ctypes         _ctypes_test    _curses
_curses_panel   _hashlib        _locale
_socket         _ssl            audioop
bz2             crypt           linuxaudiodev
nis             ossaudiodev     readline
resource        termios

_bsddb          _multiprocessing   _sqlite3
_tkinter        bsddb185        dbm
dl              gdbm            imageop
spwd            sunaudiodev

Modules/Setup.local contains recipes to compile the _ctypes and _sqlite3 modules.

Compiled on:

# Debian Buster (Linux 4.19.0-12-amd64)
$ gcc --version
gcc (Debian 8.3.0-6) 8.3.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ clang --version
Debian clang version 11.0.1-++20201103062553+ef4ffcafbb2-1~exp1~20201103053214.125
Target: x86_64-pc-linux-gnu
Thread model: posix

Also needs sh, make, objcopy, find, zip, and xargs.

1. Obtain cosmopolitan.zip amalgamation or compile any version of Cosmopolitan after (8c4cce0 July 11 2021), preferably the latest stable version.
2. Copy cosmopolitan.h (and crt.o, ape.o, ape.lds, cosmopolitan.a) to the libcosmo/ folder.
3. Run superconfigure with the appropriate $CC (calls configure with a bunch of parameters, followed by make and then objcopy to produce python.com)
4. Copy python.com to wherever and run it

cd libcosmo/
# use the latest version
wget https://justine.lol/cosmopolitan/cosmopolitan.zip
unzip cosmopolitan.zip
cd ../
CC=gcc ./superconfigure # or clang
./python.com

As of right now python.com -m pip download/install from the web doesn't work nicely because the APE does not currently have SSL support. So find some other way to get the wheels. Create a folder called Lib in the same location as python.com and unzip all necessary packages there.

./python.com -V
mkdir -p Lib/site-packages # Lib is also okay

# need to download packages from pip first, so using system python
/usr/bin/python2 -m pip download pytz

# dataclasses are not included in Python3.6 by default
./python.com -m pip --help
./python.com -m pip install ./pytz.whl -t ./Lib/site-packages

# or if pip complains for whatever reason
unzip ./pytz.whl -d ./Lib/site-packages

# check if importing works
./python.com -c 'import pytz'

Of course, only packages with the py2-none-any.whl (ie no C extensions) will import properly.

APEs are statically compiled, so no dlopen, which means you currently can't have shared objects as part of your setup. However, it is still possible to use some C extensions by compiling them like stdlib modules:

• Obtain the source for a given package my_package with an extension my_package.ext
• Move all C source files to a subfolder of Modules called my_package_ext
• Move all Python source files to a subfolder Lib (ensure directory structure is valid for the Python files).
• Change the name of C extensions and replace dots with underscores. For example, if the extension name is my_package.ext, it should now be my_package_ext. Also, there must be a function called init_my_package_ext which initializes the extension.
• Change the necessary imports in the Python source files to use my_package_ext correctly. For example, import func from .ext in my_package.__init__ would become import func from my_package_ext (no dot).
• Add the compilation recipe for the package into Modules/Setup.local.
  • The recipe format is described in Modules/Setup, and it is used to compile the C extensions for the standard library. It's basically [<extension_name> <source-files> <includes> <links>] (imagine it with gcc -o added at the start), but a little finicky, especially if you're passing stuff like -DMY_FLAG=1 (check pyexpat in Modules/Setup to see how to do it right).
• If you didn't add the recipe correctly, the Makefile will complain. Delete the makefile and run superconfigure again.
• If you added the recipe correctly, run make to check successful compilation, and then try importing the package with the ./python -c 'import my_package'.

For example, the APE includes greenlet 1.1.0 alongside the stdlib, because I wanted to try Flask 1.1.4. Modules/Setup.local contains the recipe to compile the _greenlet component of the greenlet package.