title: Highlight the text in python and save it in word file
body: <p>I am trying to take the text from word file and highlighted the required text and aging want to save the text into new word file.</p>
  
  <p>I am able to highlight the text using ANSI escape sequences but I am unable add it back to the word file.</p>
  
  <pre><code>from docx import Document
  doc = Document('t.docx')
  ##string present in t.docx '''gnjdkgdf helloworld dnvjk dsfgdzfh jsdfKSf klasdfdf sdfvgzjcv'''
  
  if 'helloworld' in doc.paragraphs[0].text:    
      high=doc.paragraphs[0].text.replace('helloworld', '\033[43m{}\033[m'.format('helloworld'))
  
  
  doc.add_paragraph(high)
  doc.save('t1.docx')
  </code></pre>
  
  <p>getting this error.</p>
  
  <pre><code>ValueError: All strings must be XML compatible: Unicode or ASCII, no NULL bytes or control characters
  </code></pre>