One 、 introduction

Recently, during the development of the project , Use Python Write a little tool for testing , one day , The test raises an incredible question ：

The result of the accumulation of decimals , It's always puzzling

So , I open it, too Python Of IDLE To test ：

forehead , It looks like this .

Through my simple thinking , I think it should be the problem that the accuracy of floating-point numbers on the bottom of the computer is not accurate , Through my Internet search related information , It also confirms my conjecture .

This blog is very good ：
Python： The problems and limitations of floating point operations

Two 、 solve

The reason is found , So how to solve the problem ？

In fact, it can be , For example, keep your results 2 Bit accuracy , So finally, add one round Method to keep the rounded digits ：

I hope this blog can bring you some help ：）