get

abstract operator fun get(i: Int): AminoAcid

Returns on AminoAcid at the given position, if negative returns from the end of the sequence

abstract operator fun get(i: Int, j: Int): ProteinSeq

abstract operator fun get(x: IntRange): ProteinSeq

Note Kotlin IntRange are inclusive end, while Python slices exclusive end Negative slices "-3..-1" start from the last base (i.e. would return the last three residues)