Custom classes that are serialized with pytree are serialized by default with `f”{class.__module__}.{class.__name__}”`. This is a dependency from our serialized program directly into the outer Python environment. If a user moves the class to a different directory, the serialized program will be unable to be loaded. So, we will require users to pass in an FQN if they want to serialize their custom treespec type.
Differential Revision: [D50886366](https://our.internmc.facebook.com/intern/diff/D50886366)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/112428
Approved by: https://github.com/suo
Part of #109684
- #109684
Changes:
- Add new functions `tree_structure`, `tree_leaves`, `tree_map_` and `tree_map_only_` to Python pytree.
- Extract reusable tests for pytree to `TestGenericPytree`.
- Change `treespec_dumps` and `treespec_loads` in C++ pytree to call Python pytree and use JSON string as serialization type.
- Rename `torch.utils.pytree` -> `torch.utils._cxx_pytree`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110395
Approved by: https://github.com/zou3519
