[change] Move console printing to StatsWriter class

[ervteng]

Proposed change(s)

Console printing was still handled in the Trainer class. This PR makes a new class (ConsoleWriter) that writes to the console; the Trainer uses this class through the StatsReporter interface as with everything else.

TODO: Move ELO writing from the GhostTrainer into the ConsoleWriter as well.

Output is slightly different than before.

Before:

2020-03-11 17:26:58 INFO [trainer.py:213] test: 3DBall: Step: 14400. Time Elapsed: 20.636 s Mean Reward: 2.200. Std of Reward: 0.000. Training.
2020-03-11 17:26:58 INFO [trainer.py:213] test: 3DBall: Step: 14436. Time Elapsed: 20.645 s Mean Reward: 1.200. Std of Reward: 0.000. Training.

After:

2020-03-11 16:51:58 INFO [stats.py:90] test_3DBall: Step: 6996. Time Elapsed: 13.717 s Mean Reward: 1.400. Std of Reward: 0.000. Training.
2020-03-11 16:51:58 INFO [stats.py:90] test_3DBall: Step: 7020. Time Elapsed: 13.744 s Mean Reward: 1.400. Std of Reward: 0.000. Training.

Types of change(s)

• Bug fix
• New feature
• Code refactor
• Breaking change
• Documentation update
• Other (please describe)

Checklist

• Added tests that prove my fix is effective or that my feature works
• Updated the changelog (if applicable)
• Updated the documentation (if applicable)
• Updated the migration guide (if applicable)

Other comments

[anupam-142857]

so it looks like category is replacing run_id. is the run_id available somewhere in the logs? can you also explain the motivation behind replacing run_id by category?

[ervteng]

run_id isn't part of the StatsWriter abstraction (but can be added if there's enough demand). By default the trainer's category is the run_id + brain_name, so the same info is available to the user. Also, the category matches what's written to TensorBoard and the filename of the CSV, so it's consistent.

[anupam-142857]

👍

[anupam-142857]

LGTM

[anupam-142857]

👍