python - Python输入=输出循环

Question

我正在尝试创建一个 python 循环，其中输出用作输入，直到输出和输入相等，这是我要解决的语句：

  1
----- = x 
 1+x

结果将比黄金比例（0.618034 ...）小1，我已经在纸上完成了，它需要大约20个循环才能获得小数点后几位的精度。请告诉我我会用什么类型的 python 循环来解决这个问题？

Answer 1

因此，根据您在此处描述的内容，您需要一个 while 循环，因为您想继续做某事，直到给定条件变为真。

lastOutput = 0; # an arbitrary starting value: the last output value 
                # needs to be shared between loop cycles, so its 
                # scope must be outside the while loop

startingValue = # whatever you start at for input
finished = False # flag for tracking whether desired value has been reached
while (!finished):
    # body of loop:
    # here, you need to take lastOutput, run it through the 
    # function again, and check if the new output value is the
    # same as the input that created it. If so, you are done,
    # so set the flag to True, and note that the correct value is now stored in lastOutput
    # If not, set the new output as lastOutput, and go again!

# ...and now finish up with whatever you want to do now that you've 
# found the value (print it, etc.)!

至于检查值是否相同的逻辑，您需要有某种阈值以达到精确目的（否则它将永远运行！），我建议在其自己的模块化方法中编写该检查清酒。

希望这会有所帮助，如果您需要我发布更多实际代码，请告诉我（我尽量不泄露太多实际代码）。