Fix saved filename in ModelCheckpoint if it already exists

[rohitgr7]

What does this PR do?

Fixes the saved filename if it's already present. It will override the file if it's already going to be deleted. Previously if save_top_k=1 and filename is static for eg: some_file, it will create a file with the version for eg: filename=some_file-v2.ckpt if max_epoch > 1 but it should be some_file.ckpt only.

The test fails on master.

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[pep8speaks]

Hello @rohitgr7! Thanks for updating this PR.

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2020-12-14 17:27:54 UTC

[codecov]

Codecov Report

Merging #4861 (dfd47dc) into master (fde972f) will decrease coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #4861   +/-   ##
======================================
- Coverage      93%     93%   -0%     
======================================
  Files         134     134           
  Lines        9907    9905    -2     
======================================
- Hits         9206    9204    -2     
  Misses        701     701           

[rohitgr7]

Thanks @carmocca for the review :)

[carmocca]

Unrelated to the PR but, is there a reason for version starting at 0?

file.ckpt  # I find this confusing, kind of implies this is -v-1
file-v0.ckpt
file-v1.ckpt
...

instead of:

file.ckpt
file-v1.ckpt
file-v2.ckpt
...

[Borda]

Unrelated to the PR but, is there a reason for version starting at 0?

there is no special reason :]
cc: @PyTorchLightning/core-contributors

[rohitgr7]

@carmocca wanna give this a shot? #4861 (comment)

[carmocca]

@carmocca wanna give this a shot? #4861 (comment)

Sure, I will. Most likely this weekend