tarekziade HF Staff
Publish MIC usage, slim fixture and reviewed Transformers expectations
1949d4a verified | # Phi-2: causal language modeling with Transformers | |
| This page is the Transformers contract of the Phi-2 MIC and also a usage example. [doc-builder](https://github.com/huggingface/doc-builder/blob/main/docs/runnable-code-blocks.md) renders the `runnable` blocks below as documentation, and its pytest plugin runs them as written against `microsoft/phi-2`. The MIC runner runs the same blocks against the slim fixture and the checkpoint in [`integration.json`](../../integration.json). Lines marked `# doc-builder: hide` only matter there: they swap in the pinned checkpoint or variant and print the result record. | |
| ## Score a batch of prompts | |
| ```py runnable:phi2 | |
| import torch | |
| from transformers import AutoModelForCausalLM, AutoTokenizer, set_seed | |
| import json # doc-builder: hide | |
| import os # doc-builder: hide | |
| model_id = "microsoft/phi-2" | |
| model_id = os.environ.get("MIC_MODEL", model_id) # doc-builder: hide | |
| variant = json.loads(os.environ.get("MIC_DEVICE_KWARGS", "{}")) # doc-builder: hide | |
| variant = json.loads(os.environ.get("MIC_MODEL_KWARGS", "{}")) # doc-builder: hide | |
| device = "cuda" if torch.cuda.is_available() else "cpu" | |
| set_seed(0) # seeds torch, NumPy, and Python: loading and dropout draw random numbers | |
| tokenizer = AutoTokenizer.from_pretrained(model_id) | |
| # phi-2 ships in float16; load float32 so the training step below needs no loss scaling | |
| model = AutoModelForCausalLM.from_pretrained(model_id, dtype=torch.float32).to(device) | |
| if variant: # doc-builder: hide | |
| del model # doc-builder: hide | |
| model = AutoModelForCausalLM.from_pretrained(model_id, **{"dtype": torch.float32, **variant}).to(device) # doc-builder: hide | |
| # phi-2's tokenizer has no pad token; left padding keeps the last position a real token | |
| if tokenizer.pad_token is None: | |
| tokenizer.pad_token = tokenizer.eos_token | |
| tokenizer.padding_side = "left" | |
| prompts = [ | |
| "def print_prime(n):\n \"\"\"\n Print all primes between 1 and n\n \"\"\"", | |
| "The capital of France is", | |
| ] | |
| inputs = tokenizer(prompts, return_tensors="pt", padding=True).to(device) | |
| with torch.no_grad(): | |
| logits = model(**inputs).logits | |
| # probe the last position (left padding puts the real last token there) | |
| probe = logits[:, -1, :] | |
| probe_ids = probe.topk(3, dim=-1).indices | |
| print(tokenizer.batch_decode(probe_ids)) | |
| ``` | |
| ## One training step | |
| ```py runnable:phi2:2 | |
| labels = inputs["input_ids"].clone() | |
| labels[inputs["attention_mask"] == 0] = -100 | |
| model.train() | |
| optimizer = torch.optim.SGD([p for p in model.parameters() if p.requires_grad], lr=0.01) | |
| loss = model(**inputs, labels=labels).loss | |
| loss.backward() | |
| before = {n: p.detach().cpu().clone() for n, p in model.named_parameters() if p.requires_grad} # doc-builder: hide | |
| optimizer.step() | |
| print(f"loss: {loss.item():.4f}") | |
| if os.environ.get("MIC_RUNNER"): # doc-builder: hide | |
| named = dict(model.named_parameters()) | |
| checked = ("model.layers.0.self_attn.q_proj.weight", "model.layers.0.mlp.fc1.weight") | |
| result = { | |
| "runtime": { | |
| "device": model.device.type, | |
| "dtype": str(model.dtype).removeprefix("torch."), | |
| "attn_implementation": model.config._attn_implementation, | |
| }, | |
| "logits": {"probe": probe.float().tolist()}, | |
| "generated_ids": probe_ids.tolist(), | |
| "training": { | |
| "loss": loss.item(), | |
| "gradients": {n: bool(named[n].grad is not None and torch.count_nonzero(named[n].grad) > 0 and torch.isfinite(named[n].grad).all()) for n in checked}, | |
| "updated": any(not torch.equal(p.detach().cpu(), before[n]) for n, p in model.named_parameters() if n in before), | |
| }, | |
| } | |
| print(json.dumps(result)) | |
| ``` | |