Parsing tags in markdown

<p><a class="wikilink" href="/luhmann_method/">Luhmann method</a> suggests using tags for categorizing entries. I am not sure how I feel about it, but for sure it can help re-discover new notes based on a topic, following an apparently random jumping process. Therefore, to be able to include tags into notes without a fixed structure, I wanted to parse the markdown file and identify strings that start with a <code>#</code>. The regex was inspired by the parses of <a href="https://github.com/renerocksai/sublimeless_zk/blob/master/src/libzk2setevi/zkutils.py">sublimeless</a>:</p> <pre class="codehilite"><code class="language-python">RE_TAGS = r&quot;(#+([^#\s.,\/!$%\^&amp;\*;{}\[\]'\&quot;=`~()&lt;&gt;”\\]|:[a-zA-Z0-9])+)&quot; </code></pre> <p>The tricky part was to add it as an extension to the markdown parser in <a class="wikilink" href="/python/">python</a> so that it would not only transform the content, but it would also store it for using in the main script. I followed a similar approach to that defined for the wikilinks:</p> <p>First, define an <code>InlineProcessor</code> that will happen after the code has been standardized. Fortunately, the extensions API is well <a href="https://python-markdown.github.io/extensions/api/">documented</a>, but I still had to go <a href="https://github.com/Python-Markdown/markdown/blob/56b03b21f50d2b28b7ab87df7d8015e1f1b62184/markdown/inlinepatterns.py#L90">to the code</a> to find out what priority to give to it. </p> <p>In my case, when I define the <code>TagExtension</code>, I use:</p> <pre class="codehilite"><code class="language-python">md.inlinePatterns.register(TagInlineProcessor(TagInlineProcessor.RE_TAGS, md), 'tags', 65) </code></pre> <p>The <strong>65</strong> means it will happen right after the <code>SimpleTextInlineProcessor</code> and the <code>AsteriskProcessor</code>, but I am not sure this is the best place.</p>