How to use the pandoc.Document function in pandoc

def get_rst(markdown_file):
            doc = pandoc.Document()
            doc.markdown = open(markdown_file).read()
            return doc.rst

def pandoc_read_md(fname):
    if 'PANDOC_PATH' not in os.environ:
        raise ImportError("No pandoc path to use")
    import pandoc
    pandoc.core.PANDOC_PATH = os.environ['PANDOC_PATH']
    doc = pandoc.Document()
    doc.markdown = read(fname)
    return doc.rst

LONG_DESCRIPTION = None
README_MARKDOWN = None

with open('README.md') as markdown_source:
    README_MARKDOWN = markdown_source.read()

if 'upload' in sys.argv:
    # Converts the README.md file to ReST, since PyPI uses ReST for formatting,
    # This allows to have one canonical README file, being the README.md
    # The conversion only needs to be done on upload.
    # Otherwise, the pandoc import and errors that are thrown when
    # pandoc are both overhead and a source of confusion for general
    # usage/installation.
    import pandoc
    pandoc.core.PANDOC_PATH = 'pandoc'
    doc = pandoc.Document()
    doc.markdown = README_MARKDOWN
    LONG_DESCRIPTION = doc.rst
else:
    # If pandoc isn't installed, e.g. when downloading from pip,
    # just use the regular README.
    LONG_DESCRIPTION = README_MARKDOWN

setup(
    name='qdb',
    version='0.1.0',
    description='Quantopian Remote Debugger for Python',
    author='Quantopian Inc.',
    author_email='opensource@quantopian.com',
    packages=find_packages(),
    scripts=['client/qdb-cli'],
    long_description=LONG_DESCRIPTION,

def pandoc_read_md(fname):
    if 'PANDOC_PATH' not in os.environ:
        raise ImportError("No pandoc path to use")
    import pandoc
    pandoc.core.PANDOC_PATH = os.environ['PANDOC_PATH']
    doc = pandoc.Document()
    doc.markdown = read(fname)
    return doc.rst

def include_readme():
    try:
        import pandoc
    except ImportError:
        return ''
    pandoc.core.PANDOC_PATH = find_executable('pandoc')
    readme_file = os.path.join(os.path.dirname(__file__), 'README.md')
    doc = pandoc.Document()
    with open(readme_file, 'r') as rf:
        doc.markdown = rf.read().encode()
        return doc.rst.decode()

if os.path.isfile(self.path):
            with open(self.path,"rb") as f:
                s = f.read()
            #Be compatible with files made on a certain android text editor that puts those bytes there sometimes.
            if s.startswith(b"\xff\xfe"):
                s = s[2:]
                self.pre_bytes = b"\xff\xfe"
            elif s.startswith(b"\xfe\xff"):
                s = s[2:]
                self.pre_bytes = b"\xfe\xff"
            elif s.startswith(b"\xef\xbb\xbf"):
                s = s[3:]
                self.pre_bytes = b"\xef\xbb\xbf"
            else:
                self.pre_bytes = b''            #now we are going to use pandoc to convert to html
            doc = pandoc.Document()

            #Figure out the input format. We back things up and archive them by appenting a Timestamp
            #to the end or else a ~. That function strips both of those things.
            if util.striptrailingnumbers(self.path).endswith(".html"):
                doc.html = s
                self.edit.page().setContentEditable(False)

            #The special html.ro lets us have read only HTML used for handy calculators and stuff.
            elif util.striptrailingnumbers(self.path).endswith(".html.ro"):
                doc.html = s
                self.edit.page().setContentEditable(False)

            elif util.striptrailingnumbers(self.path).endswith(".md"):
                doc.markdown_github = s

            elif util.striptrailingnumbers(self.path).endswith(".rst"):

if not self.edit.page().isModified():
            return

        #Back Up File
        buf =None
        #If the file exists, copy it to file~ first. If that exists, copy it to file4857475928345
        if os.path.exists(name):
            if not os.path.exists(name+"~"):
                buf=(name+"~")
                shutil.copy(name, name+"~")
            else:
                buf = name+str(time.time())
                shutil.copy(name,buf )

        #Again, pandoc to convert to the proper format
        doc = pandoc.Document()
        h = downloadAllImages(self.edit.page().mainFrame().toHtml(),name)
        doc.html = destyle_html(h).encode("utf-8")

        if  util.striptrailingnumbers(name).endswith(".md"):
            with open(name,"wb") as f:
                f.write(self.pre_bytes+doc.markdown_github)

        if  util.striptrailingnumbers(name).endswith(".rst"):
            with open(name,"wb") as f:
                f.write(self.pre_bytes+doc.rst)

        if buf and os.path.isfile(buf):
            os.remove(buf)

        #Reload to mark as saved, before the filesystem watcher ca get to it.
        self.reload()

def markdown_to_rst(src):
    pandoc.core.PANDOC_PATH = "/usr/local/bin/pandoc"
    if not os.path.exists(pandoc.core.PANDOC_PATH):
        raise Exception("Pandoc not available")

    doc = pandoc.Document()
    doc.markdown = open("README.md").read()
    return doc.rst

try:
        import subprocess
        import pandoc

        process = subprocess.Popen(
            ['which pandoc'],
            shell=True,
            stdout=subprocess.PIPE,
            universal_newlines=True)

        pandoc_path = process.communicate()[0]
        pandoc_path = pandoc_path.strip('\n')

        pandoc.core.PANDOC_PATH = pandoc_path

        doc = pandoc.Document()
        doc.markdown = long_description
        long_description = doc.rst
        open("README.rst", "w").write(doc.rst)
    except:
        if os.path.exists("README.rst"):
            long_description = open("README.rst").read()
        else:
            print("Could not find pandoc or convert properly")
            print("  make sure you have pandoc (system) and pyandoc (python module) installed")

    return long_description

try:
        import subprocess
        import pandoc

        process = subprocess.Popen(
            ['which pandoc'],
            shell=True,
            stdout=subprocess.PIPE,
            universal_newlines=True)

        pandoc_path = process.communicate()[0]
        pandoc_path = pandoc_path.strip('\n')

        pandoc.core.PANDOC_PATH = pandoc_path

        doc = pandoc.Document()
        doc.markdown = long_description
        long_description = doc.rst
        open("README.rst", "w").write(doc.rst)
    except:
        if os.path.exists("README.rst"):
            long_description = open("README.rst").read()
        else:
            print("Could not find pandoc or convert properly")
            print("  make sure you have pandoc (system) and pyandoc (python module) installed")

    return long_description