Fixes various typing errors in pytorch_lightning/strategies/deepspeed.py

[donlapark]

What does this PR do?

Fixes mypy errors in pytorch_lightning/strategies/deepspeed.py as addressed in #13445.

The code suggests that lightning_model.training is always assumed to have type pl.Trainer and not None. However, mypy does not know this and throw out an error whenever lightning_model.training is called.

In addition, mypy seems to not recognize hasattr as mentioned in this issue, causing it to throw an error on the following line (671-672) without #type: ignore:

if hasattr(train_dataloader, "batch_sampler"):
    batch_size = train_dataloader.batch_sampler.batch_size  # type: ignore[union-attr]

Does your PR introduce any breaking changes? If yes, please list them.

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[codecov]

Codecov Report

Merging #13832 (6c1cbd7) into master (a90ef3b) will increase coverage by 27%.
The diff coverage is 71%.

@@            Coverage Diff            @@
##           master   #13832     +/-   ##
=========================================
+ Coverage      49%      76%    +27%     
=========================================
  Files         332      332             
  Lines       26000    26186    +186     
=========================================
+ Hits        12728    19848   +7120     
+ Misses      13272     6338   -6934     

[otaj]

Hi @donlapark, it seems, that if you remove "pytorch_lightning.strategies.deepspeed" from pyproject.toml file, not many errors go away. I pushed the change with removal of the file from mypy ignoring so you can easily see them.

[rohitgr7]

Great work!

BTW, you can also add all suggestions in a batch and commit them at once inside the PR's Files changed section.

ref: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/incorporating-feedback-in-your-pull-request

[donlapark]

Wow, I should have known that. Thanks for the tip!

[awaelchli]

Great!