sage: x = 0.5
sage: type(x)
<class 'sage.rings.real_mpfr.RealLiteral'>
sage: x2 = float(0.5)
sage: type(x2)
<class 'float'>
sage: timeit('sleep(x)')
625 loops, best of 3: 1 µs per loop
sage: timeit('sleep(x2)')
5 loops, best of 3: 500 ms per loop
sage: # One more time for the folks in back...
sage: timeit('sleep(x)')
625 loops, best of 3: 1.01 µs per loop

sage: timeit('sleep(1.0)')
5 loops, best of 3: 1 s per loop

static int
_PyTime_FromObject(_PyTime_t *t, PyObject *obj, _PyTime_round_t round,
                   long unit_to_ns)
{
    if (PyFloat_Check(obj)) {
        double d;
        d = PyFloat_AsDouble(obj);
        if (Py_IS_NAN(d)) {
            PyErr_SetString(PyExc_ValueError, "Invalid value NaN (not a number)");
            return -1;
        }
        return _PyTime_FromFloatObject(t, d, round, unit_to_ns);
    }
    else {
        long long sec;
        Py_BUILD_ASSERT(sizeof(long long) <= sizeof(_PyTime_t));

        sec = PyLong_AsLongLong(obj);
        if (sec == -1 && PyErr_Occurred()) {
            if (PyErr_ExceptionMatches(PyExc_OverflowError))
                _PyTime_overflow();
            return -1;
        }

        if (_PyTime_check_mul_overflow(sec, unit_to_ns)) {
            _PyTime_overflow();
            return -1;
        }
        *t = sec * unit_to_ns;
        return 0;
    }
}