Creating a chest with random loot

[GS11566]

So I am trying to create a chest with random loot but I keep running into issues.
Here's a snippet:

import anvil
from random import choice, randint

loot_table = ["minecraft:poppy","minecraft:cocoa_beans"]
blocks = []

for i in range(50):
    blocks.append(anvil.Block('minecraft', 'chest', {
        "Items": [
                {
                    "Count": randint(1, 4), "Slot": j, "id": choice(loot_table)
                } for j in range(randint(1, 25))
            ]
        }
        ))

Without any modifications to NBT and anvil-parser2 module (I'm on Python 3.9.13, I removed folder names from error):

Traceback (most recent call last):
  File "\main.py", line 93, in <module>
    region.save('r.0.0.mca')
  File "\.venv\lib\site-packages\anvil\empty_region.py", line 300, in save
    nbt_data = chunk.save()
  File "\.venv\lib\site-packages\anvil\empty_chunk.py", line 176, in save
    p = s.palette()
  File "\.venv\lib\site-packages\anvil\empty_section.py", line 100, in palette
    palette = set(self.blocks)
  File "\.venv\lib\site-packages\anvil\block.py", line 54, in __hash__
    return hash(self.name()) ^ hash(frozendict(self.properties))
TypeError: unhashable type: 'list'

And I tried changing frozendict to str in block.py:

Traceback (most recent call last):
  File "\main.py", line 93, in <module>
    region.save('r.0.0.mca')
  File "\.venv\lib\site-packages\anvil\empty_region.py", line 301, in save
    nbt_data.write_file(buffer=chunk_data)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 709, in write_file
    self._render_buffer(self.file)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 425, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 425, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 510, in _render_buffer
    TAG_Byte(tag.id)._render_buffer(buffer)
AttributeError: 'list' object has no attribute 'id'

Then I tried adding this after line 164 in empty_section.py:

                    elif isinstance(value, list):
                        properties.tags.append(nbt.TAG_List(name=key, value=value))

This came out:

Traceback (most recent call last):
  File "\main.py", line 93, in <module>
    region.save('r.0.0.mca')
  File "\.venv\lib\site-packages\anvil\empty_region.py", line 301, in save
    nbt_data.write_file(buffer=chunk_data)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 709, in write_file
    self._render_buffer(self.file)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 425, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 425, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 512, in _render_buffer
    tag._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 417, in _render_buffer
    TAG_Byte(self.tagID)._render_buffer(buffer)
  File "\.venv\lib\site-packages\nbt\nbt.py", line 118, in _render_buffer
    buffer.write(self.fmt.pack(self.value))
struct.error: required argument is not an integer

Just want to add that I have never worked with NBT package.
And this snippet of the code in the beginning isn't full source code (of course), so basically I just randomly distribute blocks from blocks list in region and save that region.
Soooo..... how do I make this chest? What am I doing wrong? Is it even possible?

[GS11566]

Ohh, the properties are like /setblock ~ ~ ~ chest[properties] and not /setblock ~ ~ ~ chest{nbt}
But is there a way to make chest with random items inside it?

[0xTiger]

Ah, good question, editing block entity NBT is not really supported in anvil-parser2, apologies!
My suggestion would be to use an alternative package: amulet-core which does support this

In your example it would be something like:

from random import randint, choice

import amulet
from amulet.api.block import Block
from amulet.api.block_entity import BlockEntity
from amulet_nbt import NamedTag,  CompoundTag, ListTag, IntTag, ByteTag, StringTag


loot_table = ["minecraft:poppy", "minecraft:cocoa_beans"]
level = amulet.load_level("/path/to/your/minecraft/saves/myworld")
game_version = ("java", (1, 21, 5))


items = [
    CompoundTag({
        'count': IntTag(randint(1, 4)),
        'Slot': ByteTag(j),
        'id': StringTag(choice(loot_table))
    }) for j in range(randint(1, 25))
]
block_entity_nbt = NamedTag(CompoundTag({'Items': ListTag(items)}))
block_entity = BlockEntity(
    "minecraft", "chest",
    0, 64, 0,
    block_entity_nbt
)
block = Block("minecraft", "chest")


level.set_version_block(0, 64, 0, "minecraft:overworld", game_version, block, block_entity)
level.save()