[BugFix] to_observation_norm now works with keys which are not strings

[maxweissenbacher]

Description

Added the _key_str method in the to_observation_norm method of VecNorm. A call to to_observation_norm would have previously given an error, since in the update method, a call is made to _key_str to store the sum argument etc. However, this call was not made in to_observation_norm, resulting in the key not being able to be found in _td.

Are there any tests that need to be updated to reflect this?

I've raised this in issue #2036.

• I have raised an issue to propose this change (required for new features and bug fixes)

Types of changes

What types of changes does your code introduce? Remove all that do not apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds core functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Example (update in the folder of examples)

Checklist

Go over all the following points, and put an x in all the boxes that apply.
If you are unsure about any of these, don't hesitate to ask. We are here to help!

• I have read the CONTRIBUTION guide (required)
• My change requires a change to the documentation.
• I have updated the tests accordingly (required for a bug fix or a new feature).
• I have updated the documentation accordingly.

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/rl/2045

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❌ 14 New Failures, 1 Unrelated Failure

As of commit 74071c4 with merge base ee8cafb ():

NEW FAILURES - The following jobs have failed:

• Continuous Benchmark (PR) / CPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Continuous Benchmark (PR) / GPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Examples Tests on Linux / tests (3.9, 12.1) / linux-job (gh)
  E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jammy-updates/main/binary-amd64/Packages.gz File has unexpected size (2018947 != 2018948). Mirror sync in progress? [IP: 91.189.91.83 80]
• Habitat Tests on Linux / tests (3.9, 12.1) / linux-job (gh)
  RuntimeError: Command docker exec -t 0870fc5914935c13903a97135f84f104d53f9ebae18d5162bbdbebfe23f47246 /exec failed with exit code 139
• RLHF Tests on Linux / unittests (3.9, 12.1) / linux-job (gh)
  RuntimeError: Command docker exec -t 5ddf58552da8a64ad43af530d31f534fc534634af94fc8f2a6085114057c82c5 /exec failed with exit code 1
• Unit-tests on Linux / tests-cpu (3.10) / linux-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on Linux / tests-cpu (3.8) / linux-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on Linux / tests-cpu (3.9) / linux-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on Linux / tests-gpu (3.10, 12.1) / linux-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on Linux / tests-olddeps (3.8, 11.6) / linux-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on Linux / tests-optdeps (3.10, 12.1) / linux-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on Linux / tests-stable-gpu (3.10, 11.8) / linux-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on MacOS CPU / tests (3.8) / macos-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm
• Unit-tests on Windows / unittests-cpu / windows-job (gh)
  test/test_transforms.py::TestVecNorm::test_parallelenv_vecnorm

BROKEN TRUNK - The following job failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• Unit-tests on MacOS CPU / tests (3.11) / macos-job (gh)
  test/test_modules.py::TestMultiAgent::test_multiagent_mlp[batch1-None-False-True-3]

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[vmoens]

I took the liberty of making a couple of edits. I paved the way for this with some commented changes, I will leave them here as a suggestion for anyone who'd be interested in implementing that.

The next step is to store the tracking values in the tensordict rather than in the transform (we could add an underscore before the key string to indicate that these values are private and should not be returned by collectors for instance)