markdown_to_html.py

import re


BOLD = r"__(.*?)__", r"<strong>\1</strong>"
ITALIC = r"_(.*?)_", r"<em>\1</em>"
LIST = re.compile(r"^\* (.*)", re.M), r"<li>\1</li>"
END_LIST = re.compile(r"(<li>.*</li>)", re.S), r"<ul>\1</ul>"
HEADER = (
    (re.compile(r"^%s (.+)" % ("#" * i)), r"<h{0}>\1</h{0}>".format(i))
    for i in range(6, 0, -1)
)
PARAGRAPH = re.compile(r"^(?!<h|<li|<ul)(.*)", re.M), r"<p>\1</p>"
FLAT_TEXT = r"\n", r""
OP = BOLD, ITALIC, LIST, END_LIST, *HEADER, PARAGRAPH, FLAT_TEXT


def parse(md: str) -> str:
    """Parses Markdown to HTML

    Args:
      md (str): the markdown string to be parsed

    Returns:
      Final HTML
    """
    return [md := re.sub(*op, md) for op in OP][-1]