code: def try_read_file(s):
      
      try:
          with open(s, 'r') as f:
              data = f.read()
      except FileNotFoundError:
          # Not a file name.
          return s
      except EnvironmentError as ex:
          print_err('\nFailed to read file: {}\n  {}'.format(s, ex))
          return None
      return data
docs: If `s` is a file name, read the file and return it's content.
          Otherwise, return the original string.
          Returns None if the file was opened, but errored during reading.