BUG: calling yt.load_sample with no arguments is broken on main

[neutrinoceros]

Bug report

Bug summary

This is a regression in yt 4.3 (dev)

I suspect it came from #4646 (cc @chrishavlin). It also shows that this path is currently not tested.

Code for reproduction

$ python -c "import yt; yt.load_sample()`

Actual outcome

One can see which sample datasets are available at: https://yt-project.org/data
or alternatively by running: yt.sample_data.api.get_data_registry_table()
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/robcleme/dev/yt-project/yt/yt/loaders.py", line 1666, in load_sample
    loadable_path, load_kwargs = _get_sample_data(
    ^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: cannot unpack non-iterable NoneType object

Expected outcome
with yt 4.2.2, no error is raised

One can see which sample datasets are available at: https://yt-project.org/data
or alternatively by running: yt.sample_data.api.get_data_registry_table()

Version Information

• Operating System: any
• Python Version: any
• yt version: 4.3.0dev0
• Other Libraries (if applicable): N/A

[chrishavlin]

Yup, my pr seems the likely culprit. Happy to put in a fix later today if you don't get to it first :)

[neutrinoceros]

Be my guest !