feat(wandb): let wandb cli handle runs

[borisdayma]

What does this PR do?

With the release of wandb version >.0.10, the logic for reinit should be handled directly by wandb instead of forcing it to be True in the logger. This allows better handling of runs in jupyter/colab.

In addition, a new run should not be created if it is already existing as it creates unexpected behavior (automatically closing a run manually launched or run by a sweep).

If a user needs to create multiple runs in the same script, he can now just call wandb.finish() at any moment (which was not available previously).

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• Did you make sure to update the documentation with your changes? N/A
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• Did you verify new and existing tests pass locally with your changes?
• If you made a notable change (that affects users), did you update the CHANGELOG?

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[borisdayma]

This should not change how the callback is used.
Not sure if I'm supposed to update the CHANGELOG in this case.

[pep8speaks]

Hello @borisdayma! Thanks for updating this PR.

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

Comment last updated at 2020-11-23 18:46:05 UTC

[codecov]

Codecov Report

Merging #4648 (6b08489) into master (404af43) will increase coverage by 0%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #4648    +/-   ##
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  Coverage      93%     93%            
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  Files         118     118            
  Lines        8910    9020   +110     
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+ Hits         8284    8393   +109     
- Misses        626     627     +1     

[tchaton]

Should we handle legacy there ?

[borisdayma]

That's a good question. The new wandb CLI appeared in v0.10.0 (9/11/2020). However the reinit logic has actually changed for several months (though it's probably the most robust in the latest versions).

Using the latest version of wandb should not be a breaking change since reinit was forced to True and now it will automatically do what should be expected (ie start a run only when none is existing). Also it's now directly accessible through environment variables if users needed to set it to True for some reasons.

[borisdayma]

I added a test to check wandb.init was called only when required

[borisdayma]

Hi guys, just checking if you need anything else from me

[awaelchli]

@borisdayma I'm currently checking why tests are failing, that's why I removed the ready label.

[awaelchli]

good catch @rohitgr7 thanks!!