code: def compare_files(path1, path2):
      # type: (str, str) -> List[str]
      
      diff = difflib.ndiff(open(path1).readlines(), open(path2).readlines())
      return [x for x in diff if x[0] in ['-', '+', '?']]
docs: Returns the delta between two files using -, ?, + format excluding
      lines that are the same
  
      Args:
          path1 (str): Path to first file
          path2 (str): Path to second file
  
      Returns:
          List[str]: Delta between the two files