Wrong documentations for on_fit_* of TrainerCallbackHookMixin

[function2-llx]

Hello PyTorch Lightning team,

it seems that documentations for on_fit_* methods of TrainerCallbackHookMixin class are wrong (seems to misplace doc for on_init_start here).

https://github.com/PyTorchLightning/pytorch-lightning/blob/4dba492fb55e2862bb20f304e6bef43f1f151fc7/pytorch_lightning/trainer/callback_hook.py#L115-L139

cc @Borda @rohitgr7 @carmocca @awaelchli @ninginthecloud @daniellepintz

[daniellepintz]

Hi @function2-llx, not sure I follow exactly. The on_fit_* hooks are not deprecated, but rather the whole TrainerCallbackHookMixin is deprecated which is why you see those deprecation messages in the code snippet. What is the problem exactly?

[ananthsub]

What is the problem exactly?

The docs reference this line:

     Called when the trainer initialization begins, model has not yet been set. 

Which is not true for on_fit_start

[function2-llx]

What is the problem exactly?

The docs reference this line:

     Called when the trainer initialization begins, model has not yet been set. 

Which is not true for on_fit_start

Exactly! Thanks.

[awaelchli]

This used to be true but not anymore. It has changed roughly around the work we did on #10896 and such a doc update got easily missed. A PR for correcting this would be very welcomed ❤️