Check in a simple pure-python based Markdown previewer.

third_party/Python-Markdown/markdown/extensions/sane_lists.py

+"""
+Sane List Extension for Python-Markdown
+=======================================
+
+Modify the behavior of Lists in Python-Markdown to act in a sane manor.
+
+See <https://pythonhosted.org/Markdown/extensions/sane_lists.html>
+for documentation.
+
+Original code Copyright 2011 [Waylan Limberg](http://achinghead.com)
+
+All changes Copyright 2011-2014 The Python Markdown Project
+
+License: [BSD](http://www.opensource.org/licenses/bsd-license.php)
+
+"""
+
+from __future__ import absolute_import
+from __future__ import unicode_literals
+from . import Extension
+from ..blockprocessors import OListProcessor, UListProcessor
+import re
+
+
+class SaneOListProcessor(OListProcessor):
+
+    CHILD_RE = re.compile(r'^[ ]{0,3}((\d+\.))[ ]+(.*)')
+    SIBLING_TAGS = ['ol']
+
+
+class SaneUListProcessor(UListProcessor):
+
+    CHILD_RE = re.compile(r'^[ ]{0,3}(([*+-]))[ ]+(.*)')
+    SIBLING_TAGS = ['ul']
+
+
+class SaneListExtension(Extension):
+    """ Add sane lists to Markdown. """
+
+    def extendMarkdown(self, md, md_globals):
+        """ Override existing Processors. """
+        md.parser.blockprocessors['olist'] = SaneOListProcessor(md.parser)
+        md.parser.blockprocessors['ulist'] = SaneUListProcessor(md.parser)
+
+
+def makeExtension(*args, **kwargs):
+    return SaneListExtension(*args, **kwargs)