TypeError: 'bool' object is not callable on import on python 3.7 without typing_extensions

[otaj]

🐛 Bug report

When running on python<3.8, where there is not typing.final without typing_extensions installed, importing jsonargparse produces the TypeError.

   File ".actions/assistant.py", line 17, in <module>
    import jsonargparse
  File "/opt/hostedtoolcache/Python/3.7.14/x64/lib/python3.7/site-packages/jsonargparse/__init__.py", line 9, in <module>
    from .actions import *
  File "/opt/hostedtoolcache/Python/3.7.14/x64/lib/python3.7/site-packages/jsonargparse/actions.py", line 12, in <module>
    from .loaders_dumpers import get_loader_exceptions, load_value
  File "/opt/hostedtoolcache/Python/3.7.14/x64/lib/python3.7/site-packages/jsonargparse/loaders_dumpers.py", line 10, in <module>
    from .optionals import import_jsonnet, omegaconf_support
  File "/opt/hostedtoolcache/Python/3.7.14/x64/lib/python3.7/site-packages/jsonargparse/optionals.py", line 45, in <module>
    if not getattr(final(Namespace()), '__final__', False):

The problem is in the line above (44 in optionals.py), where fallback import returns False, which is definitely not callable.

To reproduce

install jsonargparse on python 3.7 without any extras and import

Expected behavior

No TypeError

Environment

• jsonargparse version (e.g., 4.8.0): latest at the moment of writing (4.15.2)
• Python version (e.g., 3.9): 3.7
• How jsonargparse was installed (e.g. pip install jsonargparse[all]): pip install jsonargparse
• OS (e.g., Linux): Any

[mauvilsa]

This is fixed in commit bdc528b.

[otaj]

Awesome, thanks!

[carmocca]

@otaj we should revert Lightning-AI/pytorch-lightning@bbf34fc now

[otaj]

@carmocca I don't think we should, since this is still not available on PyPI yet. Once it will become available, we can revert it