In fact, I am trying to use that extension for rendering the ipython notebook, with "markdown.extensions.codehilite(css_class=highlight)".

It crashed for me when rendering a snippet like this:

```
blah
```

The error was something with needing ptyprocess which I thought was scary. So I disabled it.

What a pity. Have you tried

```text
blah 
    ```
 

No--but the point is that there's (at this point) tons of course content that uses that--so the only real option would be to fix Python-Markdown.