[Bug Report] Text Space has limited support for multi-char symbols

[DanielGardin]

Describe the bug

I was messing around with categorical actions, where one word out of a predefined word set could be selected (e.g. "sit", "walk", "fly"). My first attempt as to define the charset as the whole words and limit the size to 1

S = frozenset(['sit', 'walk', 'fly'])
space = Text(max_length=1, charset=S)

It actually worked, and I was very glad this could be supported. However it seems like the contains implementation for this space has the supposition that all strings in charset have length 1 (which makes sense as its primary use is to store characters). Therefore, space.contains('sit') always returns False, even if it should be True.

    ...

    def contains(self, x: Any) -> bool:
        """Return boolean specifying if x is a valid member of this space."""
        if isinstance(x, str):
            if self.min_length <= len(x) <= self.max_length:
                return all(c in self.character_set for c in x)

        return False

Should Text allow multi-char symbols?

Code example

from gymnasium.spaces import Text

S = frozenset(['sit', 'walk', 'fly'])
space = Text(max_length=1, charset=S)

assert space.contains('sit') # Assertion Error

System info

Gymnasium was installed via pip in a conda environment
Gymnasium version: 1.0.0
OS: Ubuntu 20.04
Python version: 3.11.11

Additional context

No response

Checklist

• I have checked that there is no similar issue in the repo

[pseudo-rnd-thoughts]

Thanks for the issue

Interestingly, this is not how the space was meant to be used. The intention is that each element of the charset has length == 1.

If you want categorical actions, I would recommend using Discrete with some converter wrapper to change between the categorical words and discrete values.