TypeError: __init__() got an unexpected keyword argument 'num_workers'

Hi, i’ve just started getting to grips with Nornir and YAML. I have created the config.yaml, hosts.yaml and groups.yaml files in notepad++ and have only have these 3 lines of code to start with in python:

from nornir import InitNornir
nr = InitNornir(config_file="C:/Users/<REMOVED>/Desktop/config.yaml")
nr.filter(site="uk").inventory.hosts.keys()

I’m getting these errors:

Traceback (most recent call last):
  File "C:/Users/<REMOVED>/PycharmProjects/test_project/nornir_test.py", line 2, in <module>
    nr = InitNornir(config_file="C:/Users/<REMOVED>/Desktop/config.yaml")
  File "C:\Users\<REMOVED>\PycharmProjects\test_project\venv\lib\site-packages\nornir\init_nornir.py", line 64, in InitNornir
    config = Config.from_file(config_file, **kwargs)
  File "C:\Users\<REMOVED>\PycharmProjects\test_project\venv\lib\site-packages\nornir\core\configuration.py", line 308, in from_file
    core=CoreConfig(**{**data.get("core", {}), **core}),
TypeError: __init__() got an unexpected keyword argument 'num_workers'

My config.yaml file looks like this:

---
core:
    num_workers: 10

inventory:
    plugin: nornir.plugins.inventory.simple.SimpleInventory
    options:
        host_file: "C:/Users/<REMOVED>/Desktop/hosts.yaml"
        groups_file: "C:/Users/<REMOVED>/Desktop/groups.yaml"

Any help with this would be much appreciated, go easy i’m just a newbie with Nornir