If Condition Issues

I have made a simple game for python in a function called (game()). I made an IF condition within a While loop that asks a person if he wants to play the game again (yes=execute game(), no=break) but im facing an issue if the user didnt put neither yes nor no. how do I make it repeat the IF block until the user either put either yes or no. The code is shown as below. Thanks

while True:
     game()
     user=input("Do you want to play again? \n")
     if user=="yes":
        game()
     elif user=="no":
         print("Game is over")
         break
     else:
        ("Please Enter Yes or no") `

Solution

You can do something like:

play = "yes"
while play == "yes":
    game()
    play = "unknown"
    while play not in ["yes", "no"]:
        play = input("Play again (yes/no)? ").lower().strip()

This does the following:

Assumes initial play value of yes to play the game at least once.
Ensure the user answers yes or no (ignoring case and leading or trailing white space).
Continues the loop only for the yes case.

There's improvements you can make if, for example, you want a different message when user enters an invalid response, but that code should be a good start.

If you do decide it needs more features, that's probably when you could argue it would be better in a helper function, something like:

def ask(prompt, allowed):
    resp = input(prompt).lower().strip()
    while resp not in allowed:
        print(f"*** Not one of [{", ".join(allowed)}]")
        resp = input(prompt).lower().strip()
    return resp

game()
while ask("Play again (yes/no)? ", ["yes", "no"]) == "yes":
    game()

Putting it into a helper function means that you can add all sorts of wonderful features as needs require, probably with default-value parameters so the most common case doesn't require them, just by changing that one function.

For example, you may want to allow for a different subsequent prompt and making it case sensitive or not:

def _ask_case(value, ignore_case):
    return value.lower() if ignore case else value

def ask(prompt, allowed, prompt2=None, ignore_case=True):
    if prompt2 is None:
        prompt2 = prompt
    if ignore_case:
        allowed = [item.lower() for item in allowed]
    str_allow = f"*** Not one of [{', '.join(allowed)}]"

    resp = _ask_case(input(prompt).strip(), ignore_case)
    while resp not in allowed:
        print(str_allow)
        resp = _ask_case(input(prompt2).strip(), ignore_case)

    return resp

I haven't tested that code (so it may not work) and it may not be immediately necessary for your purposes, but the idea is just to show that refactoring it into a helper function means you can use it everywhere, and very simply, but still have a lot of power if or when you need it.