Simple zipapp maker

simplepyz.py

#!/usr/bin/env python3
"""
A little script to make minimal pyz packages for zipsafe programs.

NOTE: zip safe means:
* No package expects to be able to use open() to access data it shipped with
* No compiled modules
"""
import argparse
import os
import shutil
import subprocess
import sys
import tempfile
import zipapp


def do_pip(workingdir, pipargs, **_):
    print(f"Installing packages {' '.join(pipargs)}")
    proc = subprocess.run([
        sys.executable, '-m', 'pip', 'install',
        '--isolated', '--target', workingdir,
        '--system',  # Because debian
        *pipargs,
    ])
    if proc.returncode != 0:
        sys.exit(f"pip returned code {proc.returncode}")


def do_files(workingdir, extrafiles, **_):
    for fn in extrafiles:
        print(f"Copying {fn}")
        shutil.copy(fn, os.path.join(workingdir, fn))


def do_package(workingdir, destfile=None, mainfile=None, **_):
    print(f"Building {destfile}")
    if mainfile is None:
        main = None
    elif os.path.isfile(mainfile):
        shutil.copy(mainfile, os.path.join(workingdir, '__main__.py'))
        main = None
    else:
        main = mainfile

    kwargs = {}
    if sys.version_info >= (3, 7):
        kwargs = dict(
            filter=None,  # TODO, to filter `bin` and `*.dist-info`
            compressed=True,
        )
    zipapp.create_archive(
        source=workingdir,
        target=destfile,
        interpreter=f"{sys.executable} -IO",
        main=main,
        **kwargs,
    )


STEPS = [
    do_pip,
    do_files,
    do_package,
]


def parse_args(argv=None):
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('packages', nargs='*', metavar="<requirement specifier>",
                        help='packages to include')
    parser.add_argument('-r', '--requirement', metavar="<file>",
                        action='append', dest='reqfiles', default=(),
                        help='Install from the given requirements file. This option can be used multiple times.')
    parser.add_argument('-m', '--main', metavar="<file|module:function>",
                        required=True,
                        help='Main script or callable')
    parser.add_argument('-o', '--output', metavar="<file>", default="app.pyz",
                        help='File to output to')

    return parser.parse_args(argv)


def assemble_pipargs(opts):
    pips = []
    files = []
    for reqfile in opts.reqfiles:
        pips += ['-r', reqfile]
    for pkg in opts.packages:
        if os.path.isfile(pkg):
            files.append(pkg)
        else:
            pips.append(pkg)
    return pips, files


def main(argv=None):
    opts = parse_args(argv)
    pipargs, extrafiles = assemble_pipargs(opts)
    with tempfile.TemporaryDirectory() as td:
        kwargs = {
            'workingdir': td,
            'pipargs': pipargs,
            'extrafiles': extrafiles,
            'destfile': opts.output,
            'mainfile': opts.main,
        }
        for func in STEPS:
            func(**kwargs)

if __name__ == '__main__':
    main()