我应该如何检查一个条件，如果不是真的，重复上一步？(How should I check for a condition and when not true, repeat a previous st

我应该如何检查一个条件，如果不是真的，重复上一步？(How should I check for a condition and when not true, repeat a previous step?)

我正在尝试python代码的初学者级别，我希望项目检查某个变量是否被赋予1或0. 1和0表示加法或减法的选择。

代码如下：

print("This program can be used to add and subtract") x=int(input("x:")) y=int(input("y:")) print("Choose for addition :1 or subtraction 0") z = int(input("z:")) if z==1: print("Addition selected.") a= x+y print("The sum of ",y,"and",x,"is",a) elif z ==0: print("Subtraction selected.") a= x-y print("The difference between ",y,"and",x,"is",a) else: print("Kindly input either 1 or 0")

我想运行它，以便当z不等于1或0时，它将重定向用户为z选择一个值，直到没有选择正确的值！

提前致谢！

I'm trying the beginner level of python code, where I want the project to check if a certain variable has been given either 1 or 0. 1 and 0 represent the selection of addition or subtraction.

The code is given below:

print("This program can be used to add and subtract") x=int(input("x:")) y=int(input("y:")) print("Choose for addition :1 or subtraction 0") z = int(input("z:")) if z==1: print("Addition selected.") a= x+y print("The sum of ",y,"and",x,"is",a) elif z ==0: print("Subtraction selected.") a= x-y print("The difference between ",y,"and",x,"is",a) else: print("Kindly input either 1 or 0")

I want to run it so that when z is not equal to 1 or zero, it redirects user to pick one value for z again, till the correct value isn't selected!

Thanks in advance!

最满意答案

您可以将第一部分代码放入方法中，以便可以重复使用它。 喜欢这个：

z = 0 def getInput(): print("This program can be used to add and subtract") x=int(input("x:")) y=int(input("y:")) print("Choose for addition :1 or subtraction 0") z = int(input("z:"))

z需要在方法之外，以便可以从方法之外调用它。

然后，你可以改变你的代码

else: getInput()

You can put the first half of the code in a method so that you can reuse it. Like this:

z = 0 def getInput(): print("This program can be used to add and subtract") x=int(input("x:")) y=int(input("y:")) print("Choose for addition :1 or subtraction 0") z = int(input("z:"))

The z needs to be outside of the method so that it can be called from outside of the method also.

Then, you can change your code to

else: getInput()