Closes#917
### Internal Improvements
- Better variable names related to model outputs (logits, dist input
etc.). #1032
- Improved typing for actors and critics, using Tianshou classes like
`Actor`, `ActorProb`, etc.,
instead of just `nn.Module`. #1032
- Added interfaces for most `Actor` and `Critic` classes to enforce the
presence of `forward` methods. #1032
- Simplified `PGPolicy` forward by unifying the `dist_fn` interface (see
associated breaking change). #1032
- Use `.mode` of distribution instead of relying on knowledge of the
distribution type. #1032
### Breaking Changes
- Changed interface of `dist_fn` in `PGPolicy` and all subclasses to
take a single argument in both
continuous and discrete cases. #1032
---------
Co-authored-by: Arnau Jimenez <arnau.jimenez@zeiss.com>
Co-authored-by: Michael Panchenko <m.panchenko@appliedai.de>
- Added nbqa to pyproject.toml
- Resolved mypy issues on notebooks and related files
- Conducting ruff checks on notebooks
- Add DataclassPPrintMixin for better stats representation
- Improved Notebooks wording and explanations
Resolve: #1004
Related to #974
This PR adds strict typing to the output of `update` and `learn` in all
policies. This will likely be the last large refactoring PR before the
next release (0.6.0, not 1.0.0), so it requires some attention. Several
difficulties were encountered on the path to that goal:
1. The policy hierarchy is actually "broken" in the sense that the keys
of dicts that were output by `learn` did not follow the same enhancement
(inheritance) pattern as the policies. This is a real problem and should
be addressed in the near future. Generally, several aspects of the
policy design and hierarchy might deserve a dedicated discussion.
2. Each policy needs to be generic in the stats return type, because one
might want to extend it at some point and then also extend the stats.
Even within the source code base this pattern is necessary in many
places.
3. The interaction between learn and update is a bit quirky, we
currently handle it by having update modify special field inside
TrainingStats, whereas all other fields are handled by learn.
4. The IQM module is a policy wrapper and required a
TrainingStatsWrapper. The latter relies on a bunch of black magic.
They were addressed by:
1. Live with the broken hierarchy, which is now made visible by bounds
in generics. We use type: ignore where appropriate.
2. Make all policies generic with bounds following the policy
inheritance hierarchy (which is incorrect, see above). We experimented a
bit with nested TrainingStats classes, but that seemed to add more
complexity and be harder to understand. Unfortunately, mypy thinks that
the code below is wrong, wherefore we have to add `type: ignore` to the
return of each `learn`
```python
T = TypeVar("T", bound=int)
def f() -> T:
return 3
```
3. See above
4. Write representative tests for the `TrainingStatsWrapper`. Still, the
black magic might cause nasty surprises down the line (I am not proud of
it)...
Closes#933
---------
Co-authored-by: Maximilian Huettenrauch <m.huettenrauch@appliedai.de>
Co-authored-by: Michael Panchenko <m.panchenko@appliedai.de>
