This script will place blocks under the player while walking around.
# Import the minecraft library import mcpi.minecraft import Minecraft import time # connect to the minecraft client mc = Minecraft.create() # cobblestone blockType = 4 # place blocks under the player while True: pos = mc.player.getTilePos() height = mc.getHeight(pos.x, pos.y) mc.setBlock(pos.x, pos.y - 1, pos.z, blockType) time.sleep(0)