new_contents: from lxml import etree
  import os
  from os.path import join
  
  def prettify_xml_in_directory(input_directory, output_directory):
    # WARNING - will overwrite files in the output directory if there are any name conflicts
      parser = etree.XMLParser(remove_blank_text=True)
      for filename in os.listdir(input_directory):
          if filename.endswith(".xml"):
              print("Prettifying {0}...".format(filename))
              xml = etree.parse(join(input_directory, filename), parser)
              with open(output_directory + filename, mode='w') as f:
                  f.write(etree.tostring(xml, pretty_print=True))
  
subject: Create prettifydirectory.py