human
I wrote the below code

    pdfsrc = os.path.join(output_dir, u'src.pdf')
    index = os.path.join(output_dir, (u'index.' + ('xml' if as_xml else 'html')))
    with open(pdf_path, 'rb') as src:
        with open(pdfsrc, 'wb') as dest:
            shutil.copyfileobj(src, dest)
    with CurrentDir(output_dir):
        def a(x):
            return os.path.basename(x).encode('ascii')
        exe = (PDFTOHTML.encode(filesystem_encoding) if isinstance(PDFTOHTML, unicode) else PDFTOHTML)
        cmd = [exe, '-enc', 'UTF-8', '-noframes', '-p', '-nomerge', '-nodrm', a(pdfsrc), a(index)]
        if isbsd:
            cmd.remove('-nodrm')
        if no_images:
            cmd.append('-i')
        if as_xml:
            cmd.append('-xml')
        logf = PersistentTemporaryFile(u'pdftohtml_log')
        try:
            p = popen(cmd, stderr=logf._fd, stdout=logf._fd, stdin=subprocess.PIPE)
        except OSError as err:
            if (err.errno == errno.ENOENT):
                raise ConversionError(_('Could    not    find    pdftohtml,    check    it    is    in    your    PATH'))
            else:
                raise
        while True:
            try:
                ret = p.wait()
                break
            except OSError as e:
                if (e.errno == errno.EINTR):
                    continue
                else:
                    raise
        logf.flush()
        logf.close()
        out = open(logf.name, 'rb').read().strip()
        if (ret != 0):
            raise ConversionError(('pdftohtml    failed    with    return    code:    %d\n%s' % (ret, out)))
        if out:
            print 'pdftohtml    log:'
            print out
        if ((not os.path.exists(index)) or (os.stat(index).st_size < 100)):
            raise DRMError()
        if (not as_xml):
            with lopen(index, 'r+b') as i:
                raw = i.read()
                raw = flip_images(raw)
                raw = ("<!--    created    by    calibre's    pdftohtml    -->\n" + raw)
                i.seek(0)
                i.truncate()
       ...

What's a good function header?

=====
Can you provide a Python program to find    pdftohtml,    check    it    is    in    your    PATH'))?
assistant
#Here is Python program to find    pdftohtml,    check    it    is    in    your    PATH'))
.

def pdftohtml(output_dir, pdf_path, no_images, as_xml=False):