[Haskell-beginners] splitAt and negative values

Hello, Could you explain this behaviour?

splitAt (-1) "Foobar" ("","Foobar") splitAt (-100) "Foobar" ("","Foobar")

I don't understand why splitAt (-1) "Foobar" doesn't output this: ("r", "Fooba") or this: ("", "Fooba") How does it work? Python's list slicing looks similar, but results for negative values differ:

...

...

a = "Foobar" a[:-1] 'Fooba'

Thanks