Class Number

Lib/test/test_descr.py:276–289

                                                  'floordiv', 'divmod', 'mod'])

        class Number(complex):
            __slots__ = ['prec']
            def __new__(cls, *args, **kwds):
                result = complex.__new__(cls, *args)
                result.prec = kwds.get('prec', 12)
                return result
            def __repr__(self):
                prec = self.prec
                if self.imag == 0.0:
                    return "%.*g" % (prec, self.real)
                if self.real == 0.0:
                    return "%.*gj" % (prec, self.imag)
                return "(%.*g+%.*gj)" % (prec, self.real, prec, self.imag)
            __str__ = __repr__

        a = Number(3.14, prec=6)
        self.assertEqual(repr(a), "3.14")