Python保留几位小数，不进行四舍五入的方法

方法一：

def round_two(num, c):
    """
    保留2位小数，并向下取整
    :param num: 需要操作的原始数据
    :param c: 截取位数
    :return: 2位小数，并向下取整
    """
    str_num = str(num)
    if '.' in str_num and (c + 1) <= len(str_num[str_num.index('.') + 1:]):
        return float(str_num[:str_num.index('.') + 1 + c])
    else:
        return float('{:.2f}'.format(num))

方法二：

def cut(num, c):
    if c == 0:
        return int(num)
    else:
        return round(num / (10 ** c)) * (10 ** c)