mlx-examples/llms/mlx_lm/tuner/datasets.py
Chime Ogbuji cb87f6f22c Add response template (or token) argument
For use in calculating mask for everything up to the after the response prompt (i.e., the continuation/completion)
2025-02-09 07:43:01 -08:00

303 lines
9.3 KiB
Python

import json
from pathlib import Path
from typing import Dict, List, Optional
from transformers import PreTrainedTokenizer
class Dataset:
"""
Light-weight wrapper to hold a dataset.
"""
def __init__(
self,
data: List[Dict[str, str]],
tokenizer: PreTrainedTokenizer,
text_key: str = "text",
):
self._data = [tokenizer.encode(d[text_key]) for d in data]
for d in self._data:
if d[-1] != tokenizer.eos_token_id:
d.append(tokenizer.eos_token_id)
def __getitem__(self, idx: int):
return self._data[idx]
def __len__(self):
return len(self._data)
class ChatDataset:
"""
A dataset for chat data in the format of {"messages": [...]}
https://platform.openai.com/docs/guides/fine-tuning/example-format
"""
def __init__(self, data: List[Dict[str, str]], tokenizer: PreTrainedTokenizer, chat_key: str = "messages"):
self._data = [
tokenizer.apply_chat_template(
d[chat_key],
tools=d.get("tools", None),
)
for d in data
]
self._chat_key = chat_key
def __getitem__(self, idx: int):
return self._data[idx]
def __len__(self):
return len(self._data)
class CompletionsDataset:
"""
A dataset for prompt-completion data in the format of {"prompt": ..., "completion": ...}
or using user-provided keys for prompt and completion values
https://platform.openai.com/docs/guides/fine-tuning/example-format
"""
def __init__(
self,
data: List[Dict[str, str]],
tokenizer: PreTrainedTokenizer,
prompt_key: str,
completion_key: str,
response_template: Union[str, list[int]] = None,
):
self._data = [
tokenizer.apply_chat_template(
[
{"role": "user", "content": d[prompt_key]},
{"role": "assistant", "content": d[completion_key]},
],
)
for d in data
]
if isinstance(response_template, str):
self.response_token_ids = self._tokenizer.encode(
response_template, add_special_tokens=False
)
else:
self.response_token_ids = response_template
def __getitem__(self, idx: int):
return self._data[idx]
def __len__(self):
return len(self._data)
class CompletionsDatasetCollection:
def __init__(self, data: List[Union[ChatDataset, CompletionsDataset]]):
self.collection = data
def __fetch_and_process_item__(self, idx: int, handler_fn: Callable):
iteration = iter(self.collection)
item = next(iteration)
curr_idx = idx
while True:
try:
if (curr_idx + 1) <= len(item):
return handler_fn(item, curr_idx)
else:
curr_idx -= len(item)
item = next(iteration)
except StopIteration:
raise IndexError(idx)
def __getitem__(self, idx: int):
def getitem(dataset: CompletionsDataset, index: int):
return dataset[index]
return self.__fetch_and_process_item__(idx, getitem)
def get_prompt_and_completion(self, idx: int):
def getitem(dataset: CompletionsDataset, index: int):
return dataset.get_prompt_and_completion(index)
return self.__fetch_and_process_item__(idx, getitem)
def __len__(self):
return sum(map(len, self.collection))
def create_dataset(
data,
tokenizer: PreTrainedTokenizer,
prompt_feature: Optional[str] = None,
completion_feature: Optional[str] = None,
):
prompt_feature = prompt_feature or "prompt"
completion_feature = completion_feature or "completion"
sample = data[0]
if "messages" in sample:
return ChatDataset(data, tokenizer)
elif prompt_feature in sample and completion_feature in sample:
return CompletionsDataset(data, tokenizer, prompt_feature, completion_feature)
elif "text" in sample:
return Dataset(data, tokenizer)
else:
raise ValueError(
"Unsupported data format, check the supported formats here:\n"
"https://github.com/ml-explore/mlx-examples/blob/main/llms/mlx_lm/LORA.md#data."
)
def load_local_dataset(
data_path: Path,
tokenizer: PreTrainedTokenizer,
prompt_feature: Optional[str] = None,
completion_feature: Optional[str] = None,
):
def load_subset(path):
if not path.exists():
return []
with open(path, "r") as fid:
data = [json.loads(l) for l in fid]
return create_dataset(data, tokenizer, prompt_feature, completion_feature)
names = ("train", "valid", "test")
train, valid, test = [load_subset(data_path / f"{n}.jsonl") for n in names]
return train, valid, test
def load_hf_dataset(
data_id: str,
tokenizer: PreTrainedTokenizer,
prompt_feature: Optional[str] = None,
completion_feature: Optional[str] = None,
):
from datasets import exceptions, load_dataset
try:
dataset = load_dataset(data_id)
names = ("train", "valid", "test")
train, valid, test = [
(
create_dataset(
dataset[n], tokenizer, prompt_feature, completion_feature
)
if n in dataset.keys()
else []
)
for n in names
]
except exceptions.DatasetNotFoundError:
raise ValueError(f"Not found Hugging Face dataset: {data_id} .")
return train, valid, test
def load_custom_hf_dataset(args, tokenizer: PreTrainedTokenizer):
import datasets
def create_hf_dataset(
dataset_name,
text_feature,
prompt_feature,
completion_feature,
chat_feature,
split,
):
ds = datasets.load_dataset(
dataset_name,
split=split,
**hf_args.get("config", {}),
)
if prompt_feature and completion_feature:
return CompletionsDataset(ds, tokenizer, prompt_feature, completion_feature)
elif chat_feature:
return ChatDataset(ds, tokenizer, chat_key=chat_feature)
elif text_feature:
return Dataset(ds, tokenizer, text_key=text_feature)
else:
raise ValueError(
"Specify either a prompt and completion feature, a chat feature,"
" or a text feature for the Hugging Face dataset."
)
def get_train_and_valid_splits(hf_args, ds_name):
text_f = hf_args.get("text_feature", None)
prompt_f = hf_args.get("prompt_feature", None)
completion_f = hf_args.get("completion_feature", None)
chat_f = hf_args.get("chat_feature", None)
if args.train:
train_split = hf_args.get("train_split", "train[:80%]")
valid_split = hf_args.get("valid_split", "train[-10%:]")
train = create_hf_dataset(
ds_name, text_f, prompt_f, completion_f, chat_f, split=train_split
)
valid = create_hf_dataset(
ds_name, text_f, prompt_f, completion_f, chat_f, split=valid_split
)
else:
train, valid = [], []
if args.test:
test_split = hf_args.get("test_split")
test = create_hf_dataset(
ds_name, text_f, prompt_f, completion_f, chat_f, split=test_split,
)
else:
test = []
return train, valid, test
if args.datasets:
dataset_collection = args.hf_datasets
else:
dataset_collection = {"hf_dataset": args.hf_dataset}
datasets = []
for ds in dataset_collection:
hf_args = ds["hf_dataset"]
dataset_name = hf_args["name"]
print(f"Loading Hugging Face dataset {dataset_name}.")
datasets.append(get_splits(hf_args, dataset_name))
if len(datsets) == 1:
return *datasets
# Otherwise concatenate them
train, valid, test = zip(*datasets)
return tuple(map, Concatenate, zip(*datasets))
def load_dataset(args, tokenizer: PreTrainedTokenizer):
if getattr(args, "hf_dataset", False) or getattr(args, "hf_datasets", False):
train, valid, test = load_custom_hf_dataset(args, tokenizer)
else:
data_path = Path(args.data)
prompt_feature = getattr(args, "prompt_feature", None)
completion_feature = getattr(args, "completion_feature", None)
if data_path.exists():
train, valid, test = load_local_dataset(
data_path, tokenizer, prompt_feature, completion_feature
)
else:
print(f"Loading Hugging Face dataset {args.data}.")
train, valid, test = load_hf_dataset(
args.data, tokenizer, prompt_feature, completion_feature
)
if args.train and len(train) == 0:
raise ValueError(
"Training set not found or empty. Must provide training set for fine-tuning."
)
if args.train and len(valid) == 0:
raise ValueError(
"Validation set not found or empty. Must provide validation set for fine-tuning."
)
if args.test and len(test) == 0:
raise ValueError(
"Test set not found or empty. Must provide test set for evaluation."
)
return train, valid, test