Custom Checkpoint file extension

[Borda]

🚀 Feature

Atm, we have hardcoded .ckpt as a file extension for any checkpoint.

https://github.com/PyTorchLightning/pytorch-lightning/blob/db69d169e868451c16a4ee418f2de835ccce146c/pytorch_lightning/callbacks/model_checkpoint.py#L429

Proposed solution 1:

class ModelCheckpoint(Callback):
    FILE_EXTENSION = ".ckpt"

Proposed solution 2:

ModelCheckpoint(ext=''pt')

[awaelchli]

Should it be part of the filename?
Adding a new argument would require some justification I think.

[carmocca]

Some previous discussion about this: #3163 (comment)

[edenlightning]

I agree with @awaelchli, but just need to handle some edge cases (don;t think we should support "." in filenames anway, no?)

[Borda]

I agree with @awaelchli, but just need to handle some edge cases (don;t think we should support "." in filenames anway, no?)

If we define it as propose in the description, all behaviors stay the same for now... And if use overwrite it is, it is his decision and responsibility

[rohitgr7]

Should it be part of the filename?
Adding a new argument would require some justification I think.

I thought so too, but what if user wants the default filename created by PL but with a different extension? In that case it should be filename=None but one can still set different ckpt_extension.

[Borda]

well in such case you need to pass the instance of checkpoint call back anyway, so I would fo keeping untouched API inherit it...

class ModelCheckpoint(Callback):
    FILE_EXTENSION = ".ckpt"
    ...

class MyModelCheckpoint(ModelCheckpoint):
    FILE_EXTENSION = ".abc"  # only this line, nothing else is needed

so you can later pass [ModelCheckpoint(), MyModelCheckpoint()]

[Borda]

I agree with @awaelchli, but just need to handle some edge cases (don;t think we should support "." in filenames anway, no?)

as you agree with it I have reverted the description to the original one :]

[rohitgr7]

Proposed solution 1:
class ModelCheckpoint(Callback):
FILE_EXTENSION = ".ckpt"

I'd suggest this one

[janhenriklambrechts]

Ill happily work on this :)