Python：除法时，除法小于0.1时，执行除法与落地除法的结果不同 [英] Python: Different result when performing division vs. floor division when dividing <0.1

问题描述

我偶然发现了以下区别。除法50 / 0.02返回浮点数：

Accidentally I stumbled upon the following difference. The division 50/0.02 returns a float:

2500.0

但是下限分割50 // 0.02返回-在我看来-错误的答案：

However a floor division 50//0.02 returns - as it seems to me - a wrong answer:

2499.0

有人可以解释造成这种差异的原因吗？

Can anybody explain how this difference is caused?

推荐答案

这是由于python的浮点精度问题。 0.02 实际上就是Martijn Pieters建议的 0.02000000000000000041633363423443370265886187553405762 ，因此，如果将其除以50，则得出的值类似于 2499.99999999999994795875 ，并且使用下限分割，该值被下限并变为 2499 。

This is due to python's floating point precision problems. 0.02 is actually as Martijn Pieters suggested 0.02000000000000000041633363423443370265886187553405762 and so this when divided by 50 gives a value like 2499.99999999999994795875, and with floor division, this value is floored and becomes 2499.

看看 python文档以更好地了解python中的浮点数

Have a look at the python docs to have a better understanding about floating point numbers in python

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