old_contents: '''
  Smart_Strong Extension for Python-Markdown
  ==========================================
  
  This extention adds smarter handling of double underscores within words.
  
  Simple Usage:
  
      >>> import markdown
      >>> markdown.markdown('Text with double__underscore__words.', \
                            extensions=['smart_strong'])
      u'<p>Text with double__underscore__words.</p>'
      >>> markdown.markdown('__Strong__ still works.', \
                            extensions=['smart_strong'])
      u'<p><strong>Strong</strong> still works.</p>'
      >>> markdown.markdown('__this__works__too__.', \
                            extensions=['smart_strong'])
      u'<p><strong>this__works__too</strong>.</p>'
  
  Copyright 2011
  [Waylan Limberg](http://achinghead.com)
  
  '''
  
  import re
  import markdown
  from markdown.inlinepatterns import SimpleTagPattern
  
  SMART_STRONG_RE = r'(?<!\w)(_{2})(?!_)(.+?)(?<!_)\2(?!\w)'
  STRONG_RE = r'(\*{2})(.+?)\2'
  
  class SmartEmphasisExtension(markdown.extensions.Extension):
      """ Add smart_emphasis extension to Markdown class."""
  
      def extendMarkdown(self, md, md_globals):
          """ Modify inline patterns. """
          md.inlinePatterns['strong'] = SimpleTagPattern(STRONG_RE, 'strong')
          md.inlinePatterns.add('strong2', SimpleTagPattern(SMART_STRONG_RE, 'strong'), '>emphasis2')
  
  def makeExtension(configs={}):
      return SmartEmphasisExtension(configs=dict(configs))
  
  if __name__ == '__main__':
      import doctest
      doctest.testmod()
  
new_contents: '''
  Smart_Strong Extension for Python-Markdown
  ==========================================
  
  This extention adds smarter handling of double underscores within words.
  
  Simple Usage:
  
      >>> import markdown
      >>> markdown.markdown('Text with double__underscore__words.',
      ...                   extensions=['smart_strong'])
      u'<p>Text with double__underscore__words.</p>'
      >>> markdown.markdown('__Strong__ still works.',
      ...                   extensions=['smart_strong'])
      u'<p><strong>Strong</strong> still works.</p>'
      >>> markdown.markdown('__this__works__too__.',
      ...                   extensions=['smart_strong'])
      u'<p><strong>this__works__too</strong>.</p>'
  
  Copyright 2011
  [Waylan Limberg](http://achinghead.com)
  
  '''
  
  import re
  import markdown
  from markdown.inlinepatterns import SimpleTagPattern
  
  SMART_STRONG_RE = r'(?<!\w)(_{2})(?!_)(.+?)(?<!_)\2(?!\w)'
  STRONG_RE = r'(\*{2})(.+?)\2'
  
  class SmartEmphasisExtension(markdown.extensions.Extension):
      """ Add smart_emphasis extension to Markdown class."""
  
      def extendMarkdown(self, md, md_globals):
          """ Modify inline patterns. """
          md.inlinePatterns['strong'] = SimpleTagPattern(STRONG_RE, 'strong')
          md.inlinePatterns.add('strong2', SimpleTagPattern(SMART_STRONG_RE, 'strong'), '>emphasis2')
  
  def makeExtension(configs={}):
      return SmartEmphasisExtension(configs=dict(configs))
  
  if __name__ == '__main__':
      import doctest
      doctest.testmod()
  
subject: Fix syntax error in doctests which tripped up the 2to3 tool.