code: def read(in_path):
      
      assert os.path.exists(in_path), "The following GRP file can't be found. in_path: {}".format(in_path)
  
      with open(in_path, "r") as f:
          lines = f.readlines()
          # need the second conditional to ignore comment lines
          grp = [line.strip() for line in lines if line and not re.match("^#", line)]
  
      return grp
docs: Read a grp file at the path specified by in_path.
  
      Args:
          in_path (string): path to GRP file
  
      Returns:
          grp (list)