Simple Markdown Server inherited from SimpleHTTPRequestHandler. When '.md' is opening, the parsed html opens.

mdiew.py

"""
usage: mdiew.py [-h] [--bind ADDRESS] [--file FILE] [--open] [port]

positional arguments:
  port                  Specify alternate port [default: 8000]

optional arguments:
  -h, --help            show this help message and exit
  --bind ADDRESS, -b ADDRESS
                        Specify alternate bind address [default: loopback
                        address]
  --file FILE, -f FILE  Specify markdown file [default: none]
  --open, -o            Specify whether to open the browser [default: False]

requirements: markdwon
"""


from http.client import HTTPConnection
from http.server import SimpleHTTPRequestHandler, test
from io import BytesIO
import os
import urllib
import threading
import webbrowser
import time
import argparse
import markdown


class MDiewRequestHandler(SimpleHTTPRequestHandler):
    def send_head(self):
        path = self.translate_path(self.path)
        f = None
        if os.path.isdir(path):
            parts = urllib.parse.urlsplit(self.path)
            if not parts.path.endswith('/'):
                # redirect browser - doing basically what apache does
                self.send_response(301)
                new_parts = (parts[0], parts[1], parts[2] + '/',
                                parts[3], parts[4])
                new_url = urllib.parse.urlunsplit(new_parts)
                self.send_header("Location", new_url)
                self.end_headers()
                return None
            for index in "index.html", "index.htm":
                index = os.path.join(path, index)
                if os.path.exists(index):
                    path = index
                    break
            else:
                return self.list_directory(path)
        ctype = self.guess_type(path)
        try:
            if self.path.endswith('.md'):
                ctype = 'text/html'
                f = open(path, 'rt', encoding='utf-8-sig')
                fs = os.fstat(f.fileno()) 
                md = markdown.markdown(f.read(), extensions=['markdown.extensions.extra'])
                bs = md.encode()
                length = len(bs)
                f = BytesIO(bs)
            else:
                f = open(path, 'rb')
                fs = os.fstat(f.fileno())
                length = str(fs[6])
                
        except OSError:
            self.send_error(404, "File not found")
            return None
        try:
            self.send_response(200)
            self.send_header("Content-type", ctype)
            self.send_header("Content-Length", length)
            self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
            self.end_headers()
            return f
        except:
            f.close()
            raise

def boot(bind, port, filepath):
    while True:
        try:
            con = HTTPConnection(bind, port)
            con.request('HEAD', '/')
            res = con.getresponse()
            if res.status == 200:
                webbrowser.open('http://{}:{}/{}'.format(bind, port, filepath))
                break
            else:
                time.sleep(1)
        except ConnectionRefusedError:
            pass

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--bind', '-b', default='127.0.0.1', metavar='ADDRESS',
                        help='Specify alternate bind address '
                        '[default: loopback address]')
    parser.add_argument('port', action='store', default=8000, type=int,
                        nargs='?',
                        help='Specify alternate port [default: 8000]')
    parser.add_argument('--file', '-f', default='', metavar='FILE',
                        help='Specify markdown file [default: none]')
    parser.add_argument('--open', '-o', action='store_true', default=False,
                        help='Specify whether to open the browser [default: False]')

    args = parser.parse_args()
    handler = MDiewRequestHandler
    if args.open:
        threading.Thread(target=boot, daemon=True, args=(args.bind, args.port, args.file)).start()
    test(HandlerClass=handler, port=args.port, bind=args.bind)