please do not post solutions in the discourse, otherwise anyone can see it without the spoiler flag. I have added the flag to your comment.

So concise & logical!!! I though it may cause some errors reports if the size of arr is below 3.But I am wrong, because range() can handle it perfectly

So succinct! Very nice!

Mixing bool and int is like planting a bomb for your colleagues. None suits better.

What if needle does not exist in haystack ?!

saving a line break, does it really make the code faster? xD

Very nice way of getting the peak values

Had to paste this solution into VS Code and do a debug run to see how it deals with plateaus. It is really good thinking!

Wow, didn't know you could define a function with an output in one line.

molto bene! :chef's_kiss:

The one example you showed using f string doesn't seems to work for me.

Update : sorry I should have put double quotation "needle" instead of 'needle'

I do the exact same thing then see someone being cleverer as always. I learn so much from this website! Also lambda would be even shorter