pickItem 1.14+

--attempts to pick an item from your inventory
--if it exists it is picked from hotbar or moved to the prefered slot
--slot number is returned or false if none found
function pickItem(id, optHotbarSlot)
              local inv = openInventory()
              local map = inv.mapping[inv.getType()]
              local optHotbarSlot = optHotbarSlot or 1
              --scan hotbar first
              for i, j in pairs(map.hotbar) do
                      local item = inv.getSlot( j )
                      if item and item.id == id then
                              setHotbar( i )
                              return j
                      end
              end

              local scanOrder = {
                      "main", "contents", "output"
              }
              for _,iType in pairs(scanOrder)do
                      --scan player inventory
                      if map[scanOrder] then
                              for i, j in pairs(map[scanOrder])do
                                      local item = inv.getSlot(j)
                                      if item and item.id == id then
                                              local p = map.hotbar[optHotbarSlot]
                                              inv.click( j ) --pickup
                                              waitTick()
                                              inv.click( p ) --place/swap
                                              waitTick()
                                              if inv.getHeld() then --place if swaped
                                                    inv.click( j )
                                                    waitTick()
                                              end
                                              --TODO close inventory maybe
                                      return optHotbarSlot
                                      end
                              end
                      end
              end

              return false
end