I'm not sure of a stand-alone script that does just that. One way to do it via eventing is to put all your weapons on character sprite sheets, an event (initially invisible) that moves to the same location as the player, and changes this event's character graphic to the weapon you want. Make the event "walk" (aka play the swinging animation) and make the event invisible again.
If you want it to look good, you're going to have to make an effort to "pixel art". Otherwise, the best a script is going to do is rotate a small, static image (and frankly, it looks terrible).