Recursion error due to Trainer string method

[PabloVD]

Description

When printing the trainer, for instance print(runner.trainer), there is a recursion error:

    string = f"Trainer: {self}"
             ^^^^^^^^^^^^^^^^^^
  [Previous line repeated 326 more times]
RecursionError: maximum recursion depth exceeded while getting the str of an object

This is due to the fact that the str method refers to itself

    def __str__(self) -> str:
        string = f"Trainer: {self}"

What skrl version are you using?

1.4.3

What ML framework/library version are you using?

Pytorch

Additional system information

Ubuntu 22

[PabloVD]

Fixed with #374

[r2xd889zyn-dot]

seeing a recursion error when printing the trainer object (e.g., print(runner.trainer)) in skrl 1.4.3. The issue appears to come from the str implementation referencing self inside the f-string: def str(self) -> str:
string = f"Trainer: {self}"This causes str to call itself recursively until the recursion limit is hit. Referencing specific attributes or avoiding {self} inside str should resolve it. The issue reproduces consistently on Ubuntu 22 with PyTorch.