oh I just learned how to use "not in" recently but I forgot to apply it.

same here LOL

when using list comprehensions, if you have no else to add, you should use the if after the for not before it. I guess that's the reason
try it yourself.

Useful when you want to learn 'not in' list

nice job

I tried this one but it kept asking me to add an else statement

I did it this way and was so proud of myself for figuring out the list comprehension XD

OMG, thank you so much for this. I kept seeing this syntax in katas and had no idea what was going on. Appreciate it so much!

did the same hehe

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It's beautiful... I'm always in a hurry and don't think much.

then the if function won't be necessary anyways. solution still works.