Markup errors using the GrammarBot API

flag_errors.py

import requests

def flag_errors(text):
  r = requests.post("https://grammarbot.p.rapidapi.com/check", 
    data = {'text': text, 'language': 'en-US'}, 
    headers={
    'x-rapidapi-host': "grammarbot.p.rapidapi.com",
    'x-rapidapi-key': "your_rapid_api_key_2a1c27dp1af3afjsn67a3e57142d6",
    'content-type': "application/x-www-form-urlencoded"
    })
  j = r.json()
  new_text = ''
  cursor = 0
  for match in j["matches"]:
      offset = match["offset"]
      length = match["length"]
      if cursor > offset: 
          continue
      # build new_text from cursor to current offset
      new_text += text[cursor:offset]
      # next add **word**
      new_text += "**" + text[offset:(offset + length)] + "**"
      # update cursor
      cursor = offset + length
      
  # if cursor < text length, then add remaining text to new_text
  if cursor < len(text):
      new_text += text[cursor:]

  return new_text

flag_errors("We be smart. They be smart too. How doo you spel that wurd?")