wkls.countries() has no len, docs need updating, LA for Laos not found so it is possibly empty

[rbavery]

Description

>>> import wkls
>>> result = wkls["us"]["ca"].wkb()
>>> result = wkls["countries"]["LA"].wkb()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/rave/miniforge3/lib/python3.12/site-packages/wkls/core.py", line 310, in wkb
    return self._get_geom_expr("ST_AsWKB(geometry)")
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/rave/miniforge3/lib/python3.12/site-packages/wkls/core.py", line 293, in _get_geom_expr
    raise ValueError(f"No result found for: {'.'.join(self.chain)}")
ValueError: No result found for: countries.la

the docs snippet to show all countries errors

print(f"Countries: {len(wkls.countries())}")

Steps to Reproduce

see above

Environment

No response

[prantogg]

Thanks for the PR @rbavery!

I like the goal here, but I think it would be a better approach to propose adding __len__ to SedonaDB itself rather than maintaining it in wkls.

That would:

• Keep DataFrame behavior in the DataFrame library
• Avoid us needing to wrap everything in ChainableDataFrame

Happy to open an issue for that in apache/sedonadb instead.

[prantogg]

Created an issue in apache/sedona-db here - apache/sedona-db#553