code: def hex(self):
          
  
          sign = '-' if self._sign() else ''
          e = self._exponent()
          if isinstance(e, six.string_types):
              return sign + e
  
          m = self._significand()
          _, digits, _ = _mpfr_get_str2(
              16,
              0,
              m,
              ROUND_TIES_TO_EVEN,
          )
          # only print the number of digits that are actually necessary
          n = 1 + (self.precision - 1) // 4
          assert all(c == '0' for c in digits[n:])
          result = '%s0x0.%sp%+d' % (sign, digits[:n], e)
          return result
docs: Return a hexadecimal representation of a BigFloat.