
CodeLlama
Overview
The Code Llama model was proposed in Code Llama: Open Foundation Models for Code by Baptiste Rozière, Jonas Gehring, Fabian Gloeckle, Sten Sootla, Itai Gat, Xiaoqing Ellen Tan, Yossi Adi, Jingyu Liu, Tal Remez, Jérémy Rapin, Artyom Kozhevnikov, Ivan Evtimov, Joanna Bitton, Manish Bhatt, Cristian Canton Ferrer, Aaron Grattafiori, Wenhan Xiong, Alexandre Défossez, Jade Copet, Faisal Azhar, Hugo Touvron, Louis Martin, Nicolas Usunier, Thomas Scialom, Gabriel Synnaeve.
The abstract from the paper is the following:
We release Code Llama, a family of large language models for code based on Llama 2 providing state-of-the-art performance among open models, infilling capabilities, support for large input contexts, and zero-shot instruction following ability for programming tasks. We provide multiple flavors to cover a wide range of applications: foundation models (Code Llama), Python specializations (Code Llama - Python), and instruction-following models (Code Llama - Instruct) with 7B, 13B and 34B parameters each. All models are trained on sequences of 16k tokens and show improvements on inputs with up to 100k tokens. 7B and 13B Code Llama and Code Llama - Instruct variants support infilling based on surrounding content. Code Llama reaches state-of-the-art performance among open models on several code benchmarks, with scores of up to 53% and 55% on HumanEval and MBPP, respectively. Notably, Code Llama - Python 7B outperforms Llama 2 70B on HumanEval and MBPP, and all our models outperform every other publicly available model on MultiPL-E. We release Code Llama under a permissive license that allows for both research and commercial use.
Check out all Code Llama model checkpoints here and the officially released ones in the codellama org.
This model was contributed by ArthurZucker. The original code of the authors can be found here.
Usage tips and examples

The Llama2 family models, on which Code Llama is based, were trained using bfloat16, but the original inference uses float16. Let's look at the different precisions:

float32: PyTorch convention on model initialization is to load models in float32, no matter with which dtype the model weights were stored. transformers also follows this convention for consistency with PyTorch. This will be picked by default. If you want the AutoModel API to cast the load the checkpoints with the storage weights type, you must specify torch_dtype="auto", e.g. model = AutoModelForCausalLM.from_pretrained("path", torch_dtype = "auto").
bfloat16: Code Llama was trained with this precision, so we recommend using it for further training or fine-tuning.
float16: We recommend running inference using this precision, as it's usually faster than bfloat16, and evaluation metrics show no discernible degradation with respect to bfloat16. You can also run inference using bfloat16, and we recommend you check inference results with both float16 and bfloat16 after fine-tuning.

As mentioned above, the dtype of the storage weights is mostly irrelevant unless you are using torch_dtype="auto" when initializing a model using. The reason is that the model will first be downloaded (using the dtype of the checkpoints online) and then will be casted to the default dtype of torch (becomes torch.float32). If there is a specified torch_dtype, it will be used instead.

Tips:
- The infilling task is supported out of the box. You should be using the tokenizer.fill_token where you want your input to be filled.
- The model conversion script is the same as for the Llama2 family:
Here is a sample usage:

python src/transformers/models/llama/convert_llama_weights_to_hf.py \
    --input_dir /path/to/downloaded/llama/weights --model_size 7B --output_dir /output/path
Note that executing the script requires enough CPU RAM to host the whole model in float16 precision (even if the biggest versions
come in several checkpoints they each contain a part of each weight of the model, so we need to load them all in RAM).
After conversion, the model and tokenizer can be loaded via:
thon

from transformers import LlamaForCausalLM, CodeLlamaTokenizer
tokenizer = CodeLlamaTokenizer.from_pretrained("codellama/CodeLlama-7b-hf")
model = LlamaForCausalLM.from_pretrained("codellama/CodeLlama-7b-hf")
PROMPT = '''def remove_non_ascii(s: str) -> str:
    """ 
    return result
'''
input_ids = tokenizer(PROMPT, return_tensors="pt")["input_ids"]
generated_ids = model.generate(input_ids, max_new_tokens=128)
filling = tokenizer.batch_decode(generated_ids[:, input_ids.shape[1]:], skip_special_tokens = True)[0]
print(PROMPT.replace("", filling))
def remove_non_ascii(s: str) -> str:
    """ Remove non-ASCII characters from a string.

Args:
    s: The string to remove non-ASCII characters from.

Returns:
    The string with non-ASCII characters removed.
"""
result = ""
for c in s:
    if ord(c) < 128:
        result += c
return result

If you only want the infilled part:
thon

from transformers import pipeline
import torch
generator = pipeline("text-generation",model="codellama/CodeLlama-7b-hf",torch_dtype=torch.float16, device_map="auto")
generator('def remove_non_ascii(s: str) -> str:\n    """ \n    return result', max_new_tokens = 128, return_type = 1)

Under the hood, the tokenizer automatically splits by <FILL_ME> to create a formatted input string that follows the original training pattern. This is more robust than preparing the pattern yourself: it avoids pitfalls, such as token glueing, that are very hard to debug.  To see how much CPU and GPU memory you need for this model or others, try this calculator which can help determine that value.
The LLaMA tokenizer is a BPE model based on sentencepiece. One quirk of sentencepiece is that when decoding a sequence, if the first token is the start of the word (e.g. "Banana"), the tokenizer does not prepend the prefix space to the string.

Code Llama has the same architecture as the Llama2 models, refer to Llama2's documentation page for the API reference.
Find Code Llama tokenizer reference below. 

CodeLlamaTokenizer
[[autodoc]] CodeLlamaTokenizer
    - build_inputs_with_special_tokens
    - get_special_tokens_mask
    - create_token_type_ids_from_sequences
    - save_vocabulary
CodeLlamaTokenizerFast
[[autodoc]] CodeLlamaTokenizerFast
    - build_inputs_with_special_tokens
    - get_special_tokens_mask
    - create_token_type_ids_from_sequences
    - update_post_processor
    - save_vocabulary