Question

我正在尝试编写一个程序，将golden ratio返回到小数位数限制。到目前为止我所拥有的是：

def gr(n):
    a, b = 0, 1
    for x in range(0, n):
        a, b = b, a+b
    else:
        return(a)

    decimals = int(input("What amount of decimals do you want to see of the golden ratio?"))
    ratio = gr(41)/gr(40)
    print(format(ratio, '2f'))

问题是我找不到将ratio格式化为decimals中的数字的方法。

Answer 1

将precision / decimals变量传递给str.format：

decimals = int(input("What amount of decimals do you want to see of the golden ratio?"))
ratio = gr(41)/gr(40)
print("{:.{}f}".format(ratio,decimals))

示例：

In [3]: decimals = int(input("What amount of decimals do you want to see of the golden ratio?"))
What amount of decimals do you want to see of the golden ratio?5

In [4]: ratio = gr(41)/gr(40)

In [5]: print("{:.{}f}".format(ratio,decimals))
1.61803

Answer 2

以下是您尝试做的替代方案：

print(round(ratio, 2))

上面的代码段会将值ratio四舍五入到小数点后两位。所以要以十进制的整数表示，你可以这样做：

print(round(ratio, decimals))

根据python中的变量限制小数

2 个答案: