Chunking Strings

function chunk(str,parts)
    local len=math.floor(#str/parts)
    local res={}
    for i=0,parts-1 do
        table.insert(res,string.sub(str,len*i,(len*(i+1))-1))
    end
    if len*parts~=#str then
        res[#res]=string.sub(str,(len*(parts-1)))
    end
    return res
end