Python Adventures

Problem
In a webapp of mine I use markdown with the excellent Python-Markdown package. However, it doesn’t support strikethrough by default.

Solution
The good news is that you can add 3rd-party extensions to Python-Markdown. With the extension “mdx_del_ins” you can use the <del> and <ins> tags.

Here is a Python function that converts markdown to HTML:

import bleach
from markdown import markdown

def md_to_html(md):
    """
    Markdown to HTML conversion.
    """
    allowed_tags = ['a', 'abbr', 'acronym', 'b',
                    'blockquote', 'code', 'em',
                    'i', 'li', 'ol', 'pre', 'strong',
                    'ul', 'h1', 'h2', 'h3', 'p', 'br', 'ins', 'del']
    return bleach.linkify(bleach.clean(
        markdown(md, output_format='html', extensions=['nl2br', 'del_ins']),
        tags=allowed_tags, strip=True))

Input:

TODO list
---------
* ~~strikethrough in Python-Markdown~~

Output:
TODO list
* strikethrough in Python-Markdown