looker-sdk 21.20.0 throws TypeError for python 3.9.10

[rowedonalde]

Due to a change in Python's functools module that was included in the update from 3.9.9->3.9.10, looker_sdk breaks on import. The error seems to be through the cattr dependency:

  File "/opt/app/src/tvsapi/views.py", line 8, in <module>
    import looker_sdk
  File "/usr/local/lib/python3.9/site-packages/looker_sdk/__init__.py", line 32, in <module>
    from looker_sdk.sdk.api31 import methods, methods as methods31  # noqa:F401
  File "/usr/local/lib/python3.9/site-packages/looker_sdk/sdk/api31/methods.py", line 32, in <module>
    from . import models as mdls
  File "/usr/local/lib/python3.9/site-packages/looker_sdk/sdk/api31/models.py", line 11935, in <module>
    sr.converter31.register_structure_hook(
  File "/usr/local/lib/python3.9/site-packages/cattr/converters.py", line 186, in register_structure_hook
    self._structure_func.register_cls_list([(cl, func)])
  File "/usr/local/lib/python3.9/site-packages/cattr/multistrategy_dispatch.py", line 45, in register_cls_list
    self._single_dispatch.register(cls, handler)
  File "/usr/local/lib/python3.9/functools.py", line 855, in register
      raise TypeError(
TypeError: Invalid first argument to `register()`. ForwardRef('AccessToken') is not a class.

[rowedonalde]

Relevant discussion in cattrs from others who have experienced this outside of looker_sdk: python-attrs/cattrs#206

[ps-jmorrow]

We're experiencing this issue as well and it's blocking our release via GHA.

[joeldodge79]

@ps-jmorrow @rowedonalde Can you pin python at <= 3.9.9 as a workaround till I can take a look?

[ps-jmorrow]

That worked as a workaround, thanks.

[joeldodge79]

I think for now we need to restrict to python_requires=">=3.6, <=3.9.9"

[jeremytchang]

Have you all been able to pull in latest with the PR change and confirm the issue is fixed?

[alekseiloginov]

I just got some details from cattrs folks on what's need to be done for us to avoid this issue and to stop restricting the python version to <=3.9.9: python-attrs/cattrs#206 (comment)

@joeldodge79 Any idea how much of an effort this might be?

[joeldodge79]

probably a few hours to check if switching to register_structure_hook_func will work for our cases like

python/looker_sdk/sdk/api40/models.py:sr.converter40.register_structure_hook(
python/looker_sdk/sdk/api40/models.py-    ForwardRef("AccessToken"),  # type: ignore
python/looker_sdk/sdk/api40/models.py-    forward_ref_structure_hook,  # type:ignore
python/looker_sdk/sdk/api40/models.py-)

and then another few hours to update packages/sdk-codegen/src/python.gen.ts and looker_sdk.rtl.serialize.forward_ref_structure_hook

so maybe a day or two's worth of work?