code: def pdf2png(file_in, file_out):
      
      command = 'convert -display 37.5 {} -resize 600 -append {}'.format(file_in, file_out)
      _subprocess.call(_shlex.split(command))
docs: Uses `ImageMagick <http://www.imagemagick.org/>`_ to convert an input *file_in* pdf to a *file_out* png. (Untested with other formats.)
  
      Parameters
      ----------
  
      file_in : str
          The path to the pdf file to be converted.
      file_out : str
          The path to the png file to be written.