clears everything above sea level, and makes everything below dirt

mcpi-create_dirt_plane

#written by Hiradur
#Replaces any block above sea level with air and every block beneath it with dirt
#to keep processing time short it only replaces blocks from above sea level to level 64
#if you built higher you have to change the parameter

#import minecraft.py module for interaction with the world
import minecraft.minecraft as minecraft
#import minecraft block module for block ids
import minecraft.block as block
#import time for delays
import time

if __name__ == "__main__":

    #Connect to minecraft by creating a minecraft object
    #(remember: minecraft needs to be running and in a game)
    mc = minecraft.Minecraft.create()

    mc.postToChat("terraforming... this will take a few minutes...")
    mc.postToChat("minecraft will probably be unresponsive for this time.")
    mc.postToChat("If you dont want your world to be erased you have 5 seconds to close the executing terminal.")
    time.sleep(5)

    mc.postToChat("Moving you to a safe position.")
    time.sleep(1)  
    mc.player.setPos(0,70,0)
    time.sleep(1)

    mc.postToChat("Starting...")
    time.sleep(1)
    #Replace blocks above sea level with air blocks by creating a huge cuboid
    #change fifth parameter to your heighest level
    mc.setBlocks(-128, 0, -128, 128, 63, 128, block.AIR)
    #Replace blocks beneath sea level with dirt blocks
    mc.setBlocks(-128, -64, -128, 128, -2, 128, block.DIRT)
    #Adding grass on top of dirt for a nicer look
    mc.setBlocks(-128, -1, -128, 128, -1, 128, block.GRASS)

    mc.postToChat("finally done!")
    time.sleep(2)