Revert of Check in a simple pure-python based Markdown previewer.

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

-"""
-Meta Data Extension for Python-Markdown
-=======================================
-
-This extension adds Meta Data handling to markdown.
-
-See <https://pythonhosted.org/Markdown/extensions/meta_data.html>
-for documentation.
-
-Original code Copyright 2007-2008 [Waylan Limberg](http://achinghead.com).
-
-All changes Copyright 2008-2014 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 ..preprocessors import Preprocessor
-import re
-import logging
-
-log = logging.getLogger('MARKDOWN')
-
-# Global Vars
-META_RE = re.compile(r'^[ ]{0,3}(?P<key>[A-Za-z0-9_-]+):\s*(?P<value>.*)')
-META_MORE_RE = re.compile(r'^[ ]{4,}(?P<value>.*)')
-BEGIN_RE = re.compile(r'^-{3}(\s.*)?')
-END_RE = re.compile(r'^(-{3}|\.{3})(\s.*)?')
-
-
-class MetaExtension (Extension):
-    """ Meta-Data extension for Python-Markdown. """
-
-    def extendMarkdown(self, md, md_globals):
-        """ Add MetaPreprocessor to Markdown instance. """
-        md.preprocessors.add("meta",
-                             MetaPreprocessor(md),
-                             ">normalize_whitespace")
-
-
-class MetaPreprocessor(Preprocessor):
-    """ Get Meta-Data. """
-
-    def run(self, lines):
-        """ Parse Meta-Data and store in Markdown.Meta. """
-        meta = {}
-        key = None
-        if lines and BEGIN_RE.match(lines[0]):
-            lines.pop(0)
-        while lines:
-            line = lines.pop(0)
-            m1 = META_RE.match(line)
-            if line.strip() == '' or END_RE.match(line):
-                break  # blank line or end of YAML header - done
-            if m1:
-                key = m1.group('key').lower().strip()
-                value = m1.group('value').strip()
-                try:
-                    meta[key].append(value)
-                except KeyError:
-                    meta[key] = [value]
-            else:
-                m2 = META_MORE_RE.match(line)
-                if m2 and key:
-                    # Add another line to existing key
-                    meta[key].append(m2.group('value').strip())
-                else:
-                    lines.insert(0, line)
-                    break  # no meta data - done
-        self.markdown.Meta = meta
-        return lines
-
-
-def makeExtension(*args, **kwargs):
-    return MetaExtension(*args, **kwargs)