code: def open_preview(self):
          '''
          Try to open a preview of the generated document.
          Currently only supported on Windows.
          '''
          self.log.info('Opening preview...')
          if self.opt.pdf:
              ext = 'pdf'
          else:
              ext = 'dvi'
          filename = '%s.%s' % (self.project_name, ext)
          if sys.platform == 'win32':
              try:
                  os.startfile(filename)
              except OSError:
                  self.log.error(
                      'Preview-Error: Extension .%s is not linked to a '
                      'specific application!' % ext
                  )
          elif sys.platform == 'darwin':
              call(['open', filename])
          else:
              self.log.error(
                  'Preview-Error: Preview function is currently not '
                  'supported on Linux.'
              f open_preview(self):
          '''
          Try to open a preview of the generated document.
          Currently only supported on Windows.
          '''
          self.log.info('Opening preview...')
          if self.opt.pdf:
              ext = 'pdf'
          else:
              ext = 'dvi'
          filename = '%s.%s' % (self.project_name, ext)
          if sys.platform == 'win32':
              try:
                  os.startfile(filename)
              except OSError:
                  self.log.error(
                      'Preview-Error: Extension .%s is not linked to a '
                      'specific application!' % ext
                  )
          elif sys.platform == 'darwin':
              call(['open', filename])
          else:
              self.log.error(
                  'Preview-Error: Preview function is currently not '
                  'supported on Linux.'
              )
docs: Try to open a preview of the generated document.
          Currently only supported on Windows.