fix mypy typing errors in pytorch_lightning.utilities.data.py

[nandwalritik]

What does this PR do?

• mypy errors

src/pytorch_lightning/utilities/data.py:67: error: Incompatible types in "yield" (actual type "None", expected type "int")  [misc]
src/pytorch_lightning/utilities/data.py:109: error: Argument 1 to "len" has incompatible type "Union[DataLoader[Any], Iterable[Any]]"; expected "Sized"  [arg-type]
src/pytorch_lightning/utilities/data.py:119: error: Argument 1 to "has_iterable_dataset" has incompatible type "Union[DataLoader[Any], Iterable[Any]]"; expected "DataLoader[Any]"  [arg-type]
src/pytorch_lightning/utilities/data.py:131: error: Name "pl.Strategy" is not defined  [name-defined]
src/pytorch_lightning/utilities/data.py:138: error: Item "LightningDataModule" of "Union[LightningModule, LightningDataModule]" has no attribute "device"  [union-attr]
src/pytorch_lightning/utilities/data.py:190: error: Argument 2 to "_get_dataloader_init_args_and_kwargs" has incompatible type "Union[Sampler[Any], Iterable[Any]]"; expected "Optional[Sampler[Any]]"  [arg-type]
src/pytorch_lightning/utilities/data.py:241: error: Cannot access "__init__" directly  [misc]
src/pytorch_lightning/utilities/data.py:283: error: Incompatible types in assignment (expression has type "List[str]", variable has type "Set[str]")  [assignment]
src/pytorch_lightning/utilities/data.py:298: error: Incompatible types in assignment (expression has type "List[Any]", variable has type "Set[Any]")  [assignment]
src/pytorch_lightning/utilities/data.py:417: error: Argument 1 to "FastForwardSampler" has incompatible type "Optional[Sampler[Any]]"; expected "Union[Sampler[Any], Generator[Any, Any, Any]]"  [arg-type]
src/pytorch_lightning/utilities/data.py:534: error: Argument 1 to "get_len" has incompatible type "Dataset[Any]"; expected "DataLoader[Any]"  [arg-type]
Found 12 errors in 1 file (checked 240 source files)

Fix mypy errors attributed to pytorch_lightning.utilities.data.py for issue #13445

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

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Did you have fun?

Yeah

[Borda]

@nandwalritik @otaj, mind checking the conflicts 🦦

[otaj]

Hi, @nandwalritik, do you intend to keep working on this? If not, I can take it over the finish line ⚡

[Borda]

Hi, @nandwalritik, do you intend to keep working on this? If not, I can take it over the finish line zap

let's take it over, pls 🐰

[nandwalritik]

Hi, @nandwalritik, do you intend to keep working on this? If not, I can take it over the finish line ⚡

Sorry got busy with office work, you can take it over @otaj .

[otaj]

@Borda It should be finished now, ready for review.
@awaelchli I took the liberty of also typing lightning_lite/utilities/data.py since it's very much intertwined.

[awaelchli]

@otaj Thank you, and sorry for the merge conflicts when ripping apart some of these utilities. I hope it wasn't too annoying.

[codecov]

Codecov Report

Merging #13901 (2e0f6db) into master (71dadb5) will increase coverage by 2%.
The diff coverage is 84%.

@@            Coverage Diff            @@
##           master   #13901     +/-   ##
=========================================
+ Coverage      85%      86%     +2%     
=========================================
  Files         381      264    -117     
  Lines       27633    20035   -7598     
=========================================
- Hits        23372    17299   -6073     
+ Misses       4261     2736   -1525