Tokenizer `encode/decode` methods are inconsistent, TypeError: argument 'ids': 'list' object cannot be interpreted as an integer

### System Info - `transformers` version: 4.35.2 - Platform: Linux-6.5.0-14-generic-x86_64-with-glibc2.35 - Python version: 3.11.6 - Huggingface_hub version: 0.20.2 - Safetensors version: 0.4.1 - Accelerate version: not installed - Accelerate config: not found - PyTorch version (GPU?): 2.0.1+cu117 (True) - Tensorflow version (GPU?): not installed (NA) - Flax version (CPU?/GPU?/TPU?): not installed (NA) - Jax version: not installed - JaxLib version: not installed - Using GPU in script?: <fill in> - Using distributed or parallel set-up in script?: <fill in> ### Who can help? @ArthurZucker ### Information - [ ] The official example scripts - [X] My own modified scripts ### Tasks - [ ] An officially supported task in the `examples` folder (such as GLUE/SQuAD, ...) - [X] My own task or dataset (give details below) ### Reproduction Run the following code: ```python from transformers import AutoTokenizer text = "test" tokenizer = AutoTokenizer.from_pretrained("gpt2") encoded = tokenizer.encode(text, return_tensors='pt') result_text = tokenizer.decode(encoded, skip_special_tokens=True) print(text) ``` Will raise exception: ``` Traceback (most recent call last): File "main.py", line 8, in <module> tokenizer.decode(encoded, skip_special_tokens=True) File "/home/scruel/mambaforge/envs/vae/lib/python3.11/site-packages/transformers/tokenization_utils_base.py", line 3748, in decode return self._decode( ^^^^^^^^^^^^^ File "/home/scruel/mambaforge/envs/vae/lib/python3.11/site-packages/transformers/tokenization_utils_fast.py", line 625, in _decode text = self._tokenizer.decode(token_ids, skip_special_tokens=skip_special_tokens) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ TypeError: argument 'ids': 'list' object cannot be interpreted as an integer ``` ### Expected behavior Should be able to print the original text `"test"`, rather than raise an exception(`TypeError`).