phi-2-chatml

Model Card for Model ID

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Based on: https://huggingface.co/microsoft/phi-2

Summary of changes made:

1. Add new special tokens for padding ([PAD]) and ChatML tokens (<|im_start|>, <|im_start|>) for further finetuning on instruction/chat datasets
2. Resize embedding layer and final output layer

• https://huggingface.co/microsoft/phi-2/discussions/22#659d8ba950c1bbee5be6f179
  • Original embedding size is 51200, but only 50295 tokens were used
  • Resized the final embdedding matrix to avoid confusion, now aligns with tokenizer vocabulary
• https://huggingface.co/microsoft/phi-2/discussions/43#659d8d3418dc7360290a4734

Code for Reproducibility

import torch
import transformers

transformers.set_seed(42)
torch.set_default_device("cuda")

model_checkpoint = "microsoft/phi-2"
tokenizer = transformers.AutoTokenizer.from_pretrained(model_checkpoint)
model = transformers.AutoModelForCausalLM.from_pretrained(model_checkpoint, torch_dtype=torch.float16, trust_remote_code=True)

num_added_tokens = tokenizer.add_special_tokens({'additional_special_tokens': ['<|im_start|>', '<|im_end|>'], 'pad_token': '[PAD]'})
model.resize_token_embeddings(len(tokenizer))