Using or in python

Question

New to coding, having problems making foolproof input for program:

answer=input(x)
while (answer != "yes") or (answer != "no"):
    answer=input("must be 'yes' or 'no' answer")

The while loop never stops, regardless of input. What am I doing wrong?

Answer 1

Here is what I would use:

while answer not in ("yes", "no"):

Right now, your code is running continually because answer will always be not "yes" or not "no".

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Also, if you want, you can add .lower() like so:

while answer.lower() not in ("yes", "no"):

This will allow your code to handle inputs such as "Yes", "yEs", etc.

Answer 2

Everything is either not yes or not no. You want and.