Useful tools for Minecraft worlds such as removing unused chunks and finding blocks, command blocks or entities.
Tested from 1.7.10 up to 1.18.2.

pip install mcworldtools

You can simply run the command mcworldtools in a Minecraft world folder.
The script will tell you the name of your Minecraft world and - if possible, it may not be in older versions - the Minecraft version of your world.
After that you can choose which tool you want to use by stating the number of the tool.

Do NOT use these tools for a world that is currently opened (i.e. in Minecraft Singleplayer or by a Minecraft server). Doing so may lead to unintended consequences. I do NOT take any responsibility for your Minecraft world if you do that.

mcworldtools [-h] [-w WORLD] [-t TOOL] [-o OUTPUT_FILE] [-f {plain,json,yaml}] [--confirm]

• -h --help Show the help message and exit.
• -v --version Show the installed version and exit.
• -w WORLD, --world WORLD Use a different world folder than the current working directory. You can provide this option multiple times for multiple words.
• -t TOOL, --tool TOOL Choose the tool to use beforehand.
• -o OUTPUT_FILE, --output-file OUTPUT_FILE Select a file to write the output statistics to. This option is mandatory when searching for something.
• -f {plain,json,yaml}, --output-format {plain,json,yaml} The output file format. May be plain (default), json or yaml.
• -i INPUT_FILE, --input-file INPUT_FILE Select a file to read input values from. See below for more information.
• --confirm Automatically confirm any confirmation requests.

You can state dimensions in input files or when you are asked for locations when removing blocks or command blocks.
Dimensions will be returned when finding blocks, command blocks or entities.
A dimension may be one of overworld, nether or end. Please note that when using this tool on server worlds where nether and end are in seperate folders (world_nether and world_the_end) and you are executing the script on one of these, the dimension will be overworld because there is no way of detecting to which dimension the world folder is belonging.
The dimensions nether and end will only be used if the nether and end files are in a folder named WORLD_FOLDER/DIM-1 (nether) or WORLD_FOLDER/DIM1 (end).

The content of the input files stated in the command have to be in valid json format.
You don't have to specify anything in the input file, but you won't get asked for something that you specified. That is useful for automated tasks.

Here is what you can change with these input files:

{
  "inhabited_time": 0
}

• inhabited_time - The time for how long a player may have been in a chunk for it to be deleted (in seconds). Defaults to 0.

{
  "action": 1,
  "only_executing": false,
  "dimension": "overworld"
}

• action - 1 for finding command blocks.
• only_executing - If enabled, only command blocks that are either powered or in automatic mode will be found.
• dimension - The dimension in which command blocks should be searched. Set to null for all dimensions. See dimension notes for more information.

{
  "action": 2,
  "locations": [
    {
      "dimension": "overworld",
      "x": 3,
      "y": 72,
      "z": 6
    },
    {
      "dimension": "nether",
      "x": 5,
      "y": 129,
      "z": 200
    }
  ]
}

• action - 2 for removing command blocks.
• locations - A list of locations where command blocks should be removed. For dimension see the dimension notes.

{
  "action": 1,
  "id": "minecraft:zombie",
  "dimension": "overworld",
  "nbt_keys": ["OnGround", "Age"]
}

• action - 1 for finding entities.
• id - The entity id to filter entities. Set to null for all entities. You don't have to prepend it with minecraft:
• dimension - The dimension in which entities should be searched. Set to null for all dimensions. See dimension notes for more information.
• nbt_keys - A list of NBT keys to be included in the output. Set to [] (empty list) for all NBT keys. Set to null to not include any NBT keys.

{
  "action": 2,
  "remove_by": "id",
  "id": "minecraft:zombie"
}

• action - 2 for removing entities.
• remove_by - id for removing by id.
• id - The id of which entities should be removed.

{
  "action": 2,
  "remove_by": "uuid",
  "uuid": "325cdf04-8211-4f7d-8a47-79b291c1ca77"
}

• action - 2 for removing entities.
• remove_by - uuid for removing by uuid.
• uuid - The uuid of the entity to remove.

{
  "action": 2,
  "remove_by": "all"
}

• action - 2 for removing entities.
• remove_by - all for removing all entities.