Right, but creating a package is not the same as installing a package, and your comment at https://news.ycombinator.com/item?id=38083296 concerned installing.

> Can you do that without setuptools or similar?

Sure.

Here is a program which, when run, creates the zipfile "hello-1.0-py3-none-any.whl" containing the wheel for a package named "hello" along with an entry point for the command-line program also named "hello"

    # Create a wheel for a 'Hello, world!' Python package.
    #
    # To install:
    #   pip install hello-1.0-py3-none-any.whl
    #
    # To use on the command-line:
    #   hello
    #
    # To use from Python:
    #   >>> import hello
    #   >>> hello.main()
    #   Hello, world!
    #
    # To uninstall:
    #   pip uninstall hello

    import base64, hashlib, zipfile

    package_name = "hello"
    version = "1.0"

    # This will go in hello/__init__.py
    payload = """
    def main():
      print("Hello, world!")
    """

    METADATA = f"""\
    Metadata-Version: 2.1
    Name: {package_name}
    Version: {version}
    Summary: Example of a hand-built wheel.
    Home-page: http://news.ycombinator.com/
    Author: eesmith
    Author-email: eesmith@example.com
    License: Public Domain
    Platform: UNKNOWN

    UNKNOWN
    """

    # This causes the installer to create the command-line 'hello' program.
    entry_points = """\
    [console_scripts]
    hello = hello:main
    """

    WHEEL = """\
    Wheel-Version: 1.0
    Generator: eesmith_wheelgen (0.0.0)
    Root-Is-Purelib: true
    Tag: py3-none-any
    """

    top_level = f"""
    {package_name}
    """

    def build():
      wheel_name = f"{package_name}-{version}-py3-none-any.whl"
      with zipfile.ZipFile(wheel_name, "w") as zip:
        dist_info = f"{package_name}-{version}.dist-info"

        # Add a file and build up information needed for the RECORD .
        record_lines = []
        def add_file(filename, content):
          with zip.open(filename, "w") as f:
            byte_content = content.encode("utf8")
            f.write(byte_content)

          digest = hashlib.sha256(byte_content).digest()
          encoded = base64.urlsafe_b64encode(digest).rstrip(b"=")
          record_line = f"{filename},sha256={encoded},{len(byte_content)}\n"
          record_lines.append(record_line.encode("utf8"))

        add_file(f"{package_name}/__init__.py", payload)
        add_file(f"{dist_info}/METADATA", METADATA)
        add_file(f"{dist_info}/WHEEL", WHEEL)
        add_file(f"{dist_info}/entry_points.txt", entry_points)
        add_file(f"{dist_info}/top_level.txt", top_level)

        with zip.open(f"{dist_info}/RECORD", "w") as f:
          f.writelines(record_lines)

    if __name__ == "__main__":
        build()