fractions.py 文件源码

def __rfloordiv__(b, a):
        """a // b"""
        # Will be math.floor(a / b) in 3.0.
        div = a / b
        if isinstance(div, Rational):
            # trunc(math.floor(div)) doesn't work if the rational is
            # more precise than a float because the intermediate
            # rounding may cross an integer boundary.
            return div.numerator // div.denominator
        else:
            return math.floor(div)