The printing in _markdown_shortcodes/__init__.py_ (line [53](https://github.com/defbyte/django-markdown-shortcodes/blob/master/markdown_shortcodes/__init__.py#L53) and [57](https://github.com/defbyte/django-markdown-shortcodes/blob/master/markdown_shortcodes/__init__.py#L57)) should be surrounded by parentheses for python 3 compatibility.
