code: def _ordinal(n):
      
      idx = int((n//10 % 10 != 1) * (n % 10 < 4) * n % 10)
      return '{}{}'.format(n, "tsnrhtdd"[idx::4])
docs: Returns the ordinal string for a given integer
  
      See https://stackoverflow.com/a/20007730/1307974
  
      Parameters
      ----------
      n : `int`
          the number to convert to ordinal
  
      Examples
      --------
      >>> _ordinal(11)
      '11th'
      >>> _ordinal(102)
      '102nd'