pymcworld is a simple world creator for Minecraft. It currently supports 1.16.5. The library automatically takes care of level files, placing of blocks, gamerules, and more. It currently supports over 500 blocks.
Example:
from pymcworld.world import World
world = World()
world.set_block(0, 0, 0, world.blocks.ANDESITE)
world.save("testworld")
This creates a world, with the block at (0, 0, 0) set to andesite, and saves the world to the testworld folder. This is the code to create a sphere:
from pymcworld.world import World
world = World()
# this function takes 5 arguments: x, y, z, radius, and block type
world.shape.sphere(0, 20, 0, 15, world.blocks.ANDESITE)
world.save("testworld")