How to use the pypandoc.get_pandoc_version function in pypandoc

def test_get_pandoc_version(self):
        assert "HOME" in os.environ, "No HOME set, this will error..."
        version = pypandoc.get_pandoc_version()
        self.assertTrue(isinstance(version, pypandoc.string_types))
        major = int(version.split(".")[0])
        # according to http://pandoc.org/releases.html there were only two versions 0.x ...
        self.assertTrue(major in [0, 1, 2])

def has_pandoc():  # pragma: no cover
    try:
        import pypandoc
        pypandoc.get_pandoc_version()
        return True
    except ImportError:
        logger.debug("pypandoc is not installed.")
    except FileNotFoundError:
        logger.debug("pandoc is not installed.")
    return False

def download_pandoc():
    """Download pandoc if not already installed"""
    try:
        # Check whether it is already installed
        pypandoc.get_pandoc_version()
    except OSError:
        # Pandoc not installed. Let's download it silently.
        with open(os.devnull, 'w') as devnull:
            sys.stdout = devnull
            pypandoc.download_pandoc()
            sys.stdout = sys.__stdout__

        # Hack to delete the downloaded file from the folder,
        # otherwise it could get accidently committed to the repo
        # by other scripts in the repo.
        pf = sys.platform
        if pf.startswith('linux'):
            pf = 'linux'
        url = pypandoc.pandoc_download._get_pandoc_urls()[0][pf]
        filename = url.split('/')[-1]
        os.remove(filename)

# render the template to a html string
        template = get_template(template_src)
        html = template.render(context)

        # remove empty lines
        html = os.linesep.join([line for line in html.splitlines() if line.strip()])

        if format == 'html':

            # create the response object
            response = HttpResponse(html)

        else:
            if format == 'pdf':
                # check pandoc version (the pdf arg changed to version 2)
                if pypandoc.get_pandoc_version().split('.')[0] == '1':
                    args = ['-V', 'geometry:margin=1in', '--latex-engine=xelatex']
                else:
                    args = ['-V', 'geometry:margin=1in', '--pdf-engine=xelatex']

                content_disposition = 'filename="%s.%s"' % (title, format)
            else:
                args = []
                content_disposition = 'attachment; filename="%s.%s"' % (title, format)

            # use reference document for certain file formats
            refdoc = set_export_reference_document(format)
            if refdoc is not None and (format == 'docx' or format == 'odt'):
                if pypandoc.get_pandoc_version().startswith("1"):
                    refdoc_param = '--reference-' + format + '=' + refdoc
                    args.extend([refdoc_param])
                else:

temp_path = os.path.join(self.temp_root, base+EXTENSION)
        self.log.debug('Creating temp file %s' % temp_path)
        with io.open(temp_path, 'w', encoding='utf-8') as temp:
            temp.write('\n'.join(markdown))

        # extra arguments for pandoc
        extra_args = ['--highlight-style', 'pygments', '-s', '-c', self.css,
                      '--template', self.template]

        # use TOC if enabled
        if self.info.use_TOC:
            extra_args.append('--toc')

        # use KaTex
        if hasattr(pa, 'get_pandoc_version'):
            version = LooseVersion(pa.get_pandoc_version())
            if version < LooseVersion('1.13.2'):
                self.log.warning("Pandoc version %s " % pa.get_pandoc_version(),
                                 "has no support for KaTeX. Please install"
                                 " at least version 1.13.2 for math support.")
            else: # pragma: no cover
                extra_args.append('--katex')
        else: # pragma: no cover
            self.log.warning("Pypandoc version is below 0.9.7, and does not "
                             "allow to check for Pandoc version. Please "
                             "update it with pip.")

        # Apply pandoc to this markdown file, from pypandoc thin wrapper, and
        # recover the html
        html = pa.convert(temp_path, 'html', encoding='utf-8',
                          extra_args=extra_args)

def _has_pypandoc():
    """Check if pypandoc package available."""
    try:
        import pypandoc  # noqa
        # Import error raised only when function called
        version = pypandoc.get_pandoc_version()
    except (ImportError, OSError):
        return None, None
    else:
        return True, version

def common_md():
    print(f"Pandoc version:           {pypandoc.get_pandoc_version()}")
    print(f"Using docs directory:     {DOCS_DIR}")
    print(f"Using ops docs directory: {OP_DOCS_DIR}")
    print()

    html_op_list_template = env.get_template("html_op_list.jinja2.md")
    html_op_table_template = env.get_template("html_op_table.jinja2.md")
    pdf_op_table_template = env.get_template("pdf_op_table.jinja2.md")
    pdf_op_extended_template = env.get_template("pdf_op_extended.jinja2.md")

    intro = ""
    intro += Path(DOCS_DIR / "intro.md") \
        .read_text().replace("VERSION", TT_VERSION["tag"][1:]) + "\n\n"
    intro += Path(DOCS_DIR / "whats_new.md").read_text() + "\n\n"
    intro += Path(DOCS_DIR / "quickstart.md").read_text() + "\n\n"
    intro += Path(DOCS_DIR / "keys.md").read_text() + "\n\n"
    intro += Path(DOCS_DIR / "ops.md").read_text() + "\n\n"

with io.open(temp_path, 'w', encoding='utf-8') as temp:
            temp.write('\n'.join(markdown))

        # extra arguments for pandoc
        extra_args = ['--highlight-style', 'pygments', '-s', '-c', self.css,
                      '--template', self.template]

        # use TOC if enabled
        if self.info.use_TOC:
            extra_args.append('--toc')

        # use KaTex
        if hasattr(pa, 'get_pandoc_version'):
            version = LooseVersion(pa.get_pandoc_version())
            if version < LooseVersion('1.13.2'):
                self.log.warning("Pandoc version %s " % pa.get_pandoc_version(),
                                 "has no support for KaTeX. Please install"
                                 " at least version 1.13.2 for math support.")
            else: # pragma: no cover
                extra_args.append('--katex')
        else: # pragma: no cover
            self.log.warning("Pypandoc version is below 0.9.7, and does not "
                             "allow to check for Pandoc version. Please "
                             "update it with pip.")

        # Apply pandoc to this markdown file, from pypandoc thin wrapper, and
        # recover the html
        html = pa.convert(temp_path, 'html', encoding='utf-8',
                          extra_args=extra_args)

        # Convert the windows ending of lines to simple line breaks (\r\n to
        # \n)