old_contents: """
  Global wikipedia excpetion and warning classes.
  """
  
  
  class PageError(Exception):
      """Exception raised when no Wikipedia matched a query."""
  
      def __init__(self, page_title):
          self.title = page_title
  
      def __str__(self):
          return "\"%s\" does not match any pages. Try another query!" % self.title
  
  
  class DisambiguationError(Exception):
      """
      Exception raised when a page resolves to a Disambiguation page.
  
      The `options` property contains a list of titles
      of Wikipedia pages that the query may refer to.
      """
  
      def __init__(self, title, may_refer_to):
          self.title = title
          self.options = may_refer_to
  
      def __unicode__(self):
          return u"\"%s\" may refer to: \n%s" % (self.title, '\n'.join(self.options))
  
      def __str__(self):
          return unicode(self).encode('ascii', 'ignore')
  
  
  class RedirectError(Exception):
      """Exception raised when a page title unexpectedly resolves to a redirect."""
  
      def __init__(self, page_title):
          self.title = page_title
  
      def __str__(self):
          return ("\"%s\" resulted in a redirect. Set the redirect property to True to allow automatic redirects." % self.title)
  
new_contents: """
  Global wikipedia excpetion and warning classes.
  """
  
  class WikipediaException(Exception):
      """Base Wikipedia exception class."""
  
      pass
  
  
  class PageError(WikipediaException):
      """Exception raised when no Wikipedia matched a query."""
  
      def __init__(self, page_title):
          self.title = page_title
  
      def __str__(self):
          return "\"%s\" does not match any pages. Try another query!" % self.title
  
  
  class DisambiguationError(WikipediaException):
      """
      Exception raised when a page resolves to a Disambiguation page.
  
      The `options` property contains a list of titles
      of Wikipedia pages that the query may refer to.
      """
  
      def __init__(self, title, may_refer_to):
          self.title = title
          self.options = may_refer_to
  
      def __unicode__(self):
          return u"\"%s\" may refer to: \n%s" % (self.title, '\n'.join(self.options))
  
      def __str__(self):
          return unicode(self).encode('ascii', 'ignore')
  
  
  class RedirectError(WikipediaException):
      """Exception raised when a page title unexpectedly resolves to a redirect."""
  
      def __init__(self, page_title):
          self.title = page_title
  
      def __str__(self):
          return ("\"%s\" resulted in a redirect. Set the redirect property to True to allow automatic redirects." % self.title)
  
subject: add base Wikipedia exception class