Python四舍五入问题详解

def __round45r(number, digits=0):
    '''四舍五入，5一定进位，digits表示保留小数位数'''
    int_len = len(str(int(abs(number))))
    signal_ = 1 if number >= 0 else -1
    err_place = 16 - int_len - 1
    if err_place > 0:
        err_ = 10**-err_place
        return round(number + err_ * signal_, digits)
    else:
        raise NotImplemented   # 受到float表示精度的限制！

参考网址:https://blog.csdn.net/wangxichang/article/details/90606211