def byte_compile(  # noqa: C901
    py_files,
    optimize=0,
    force=0,
    prefix=None,
    base_dir=None,
    verbose=1,
    dry_run=0,
    direct=None,
):
    """Byte-compile a collection of Python source files to .pyc
    files in a __pycache__ subdirectory.  'py_files' is a list
    of files to compile; any files that don't end in ".py" are silently
    skipped.  'optimize' must be one of the following:
      0 - don't optimize
      1 - normal optimization (like "python -O")
      2 - extra optimization (like "python -OO")
    If 'force' is true, all files are recompiled regardless of
    timestamps.

    The source filename encoded in each bytecode file defaults to the
    filenames listed in 'py_files'; you can modify these with 'prefix' and
    'basedir'.  'prefix' is a string that will be stripped off of each
    source filename, and 'base_dir' is a directory name that will be
    prepended (after 'prefix' is stripped).  You can supply either or both
    (or neither) of 'prefix' and 'base_dir', as you wish.

    If 'dry_run' is true, doesn't actually do anything that would
    affect the filesystem.

    Byte-compilation is either done directly in this interpreter process
    with the standard py_compile module, or indirectly by writing a
    temporary script and executing it.  Normally, you should let
    'byte_compile()' figure out to use direct compilation or not (see
    the source for details).  The 'direct' flag is used by the script
    generated in indirect mode; unless you know what you're doing, leave
    it set to None.
    """

    # nothing is done if sys.dont_write_bytecode is True
    if sys.dont_write_bytecode:
        raise DistutilsByteCompileError('byte-compiling is disabled.')

    # First, if the caller didn't force us into direct or indirect mode,
    # figure out which mode we should be in.  We take a conservative
    # approach: choose direct mode *only* if the current interpreter is
    # in debug mode and optimize is 0.  If we're not in debug mode (-O
    # or -OO), we don't know which level of optimization this
    # interpreter is running with, so we can't do direct
    # byte-compilation and be certain that it's the right thing.  Thus,
    # always compile indirectly if the current interpreter is in either
    # optimize mode, or if either optimization level was requested by
    # the caller.
    if direct is None:
        direct = __debug__ and optimize == 0

    # "Indirect" byte-compilation: write a temporary script and then
    # run it with the appropriate flags.
    if not direct:
        try:
            from tempfile import mkstemp

            (script_fd, script_name) = mkstemp(".py")
        except ImportError:
            from tempfile import mktemp

            (script_fd, script_name) = None, mktemp(".py")
        log.info("writing byte-compilation script '%s'", script_name)
        if not dry_run:
            if script_fd is not None:
                script = os.fdopen(script_fd, "w")
            else:
                script = open(script_name, "w")

            with script:
                script.write(
                    """\
from distutils.util import byte_compile
files = [
"""
                )

                # XXX would be nice to write absolute filenames, just for
                # safety's sake (script should be more robust in the face of
                # chdir'ing before running it).  But this requires abspath'ing
                # 'prefix' as well, and that breaks the hack in build_lib's
                # 'byte_compile()' method that carefully tacks on a trailing
                # slash (os.sep really) to make sure the prefix here is "just
                # right".  This whole prefix business is rather delicate -- the
                # problem is that it's really a directory, but I'm treating it
                # as a dumb string, so trailing slashes and so forth matter.

                script.write(",\n".join(map(repr, py_files)) + "]\n")
                script.write(
                    """
byte_compile(files, optimize=%r, force=%r,
             prefix=%r, base_dir=%r,
             verbose=%r, dry_run=0,
             direct=1)
"""
                    % (optimize, force, prefix, base_dir, verbose)
                )

        cmd = [sys.executable]
        cmd.extend(subprocess._optim_args_from_interpreter_flags())
        cmd.append(script_name)
        spawn(cmd, dry_run=dry_run)
        execute(os.remove, (script_name,), "removing %s" % script_name, dry_run=dry_run)

    # "Direct" byte-compilation: use the py_compile module to compile
    # right here, right now.  Note that the script generated in indirect
    # mode simply calls 'byte_compile()' in direct mode, a weird sort of
    # cross-process recursion.  Hey, it works!
    else:
        from py_compile import compile

        for file in py_files:
            if file[-3:] != ".py":
                # This lets us be lazy and not filter filenames in
                # the "install_lib" command.
                continue

            # Terminology from the py_compile module:
            #   cfile - byte-compiled file
            #   dfile - purported source filename (same as 'file' by default)
            if optimize >= 0:
                opt = '' if optimize == 0 else optimize
                cfile = importlib.util.cache_from_source(file, optimization=opt)
            else:
                cfile = importlib.util.cache_from_source(file)
            dfile = file
            if prefix:
                if file[: len(prefix)] != prefix:
                    raise ValueError(
                        "invalid prefix: filename %r doesn't start with %r"
                        % (file, prefix)
                    )
                dfile = dfile[len(prefix) :]
            if base_dir:
                dfile = os.path.join(base_dir, dfile)

            cfile_base = os.path.basename(cfile)
            if direct:
                if force or newer(file, cfile):
                    log.info("byte-compiling %s to %s", file, cfile_base)
                    if not dry_run:
                        compile(file, cfile, dfile)
                else:
                    log.debug("skipping byte-compilation of %s to %s", file, cfile_base)
Byte-compile a collection of Python source files to .pyc
    files in a __pycache__ subdirectory.  'py_files' is a list
    of files to compile; any files that don't end in ".py" are silently
    skipped.  'optimize' must be one of the following:
      0 - don't optimize
      1 - normal optimization (like "python -O")
      2 - extra optimization (like "python -OO")
    If 'force' is true, all files are recompiled regardless of
    timestamps.

    The source filename encoded in each bytecode file defaults to the
    filenames listed in 'py_files'; you can modify these with 'prefix' and
    'basedir'.  'prefix' is a string that will be stripped off of each
    source filename, and 'base_dir' is a directory name that will be
    prepended (after 'prefix' is stripped).  You can supply either or both
    (or neither) of 'prefix' and 'base_dir', as you wish.

    If 'dry_run' is true, doesn't actually do anything that would
    affect the filesystem.

    Byte-compilation is either done directly in this interpreter process
    with the standard py_compile module, or indirectly by writing a
    temporary script and executing it.  Normally, you should let
    'byte_compile()' figure out to use direct compilation or not (see
    the source for details).  The 'direct' flag is used by the script
    generated in indirect mode; unless you know what you're doing, leave
    it set to None.
    
product/gradle-plugin/src/main/python/setuptools/_distutils/util.py