Data Utilities
trl.is_conversational
< source >( example: Dict ) → bool
Check if the example is in a conversational format.
Apply a chat template to a conversational example.
For more details, see maybe_apply_chat_template().
trl.maybe_apply_chat_template
< source >( example: Dict tokenizer: PreTrainedTokenizer ) → Dict[str, str]
Parameters
- example (
Dict[str, List[Dict[str, str]]
) — Dictionary representing a single data entry of a conversational dataset. Each data entry can have different keys depending on the dataset type. The supported dataset types are:- Language modeling dataset:
"messages"
. - Prompt-only dataset:
"prompt"
. - Prompt-completion dataset:
"prompt"
and"completion"
. - Preference dataset:
"prompt"
,"chosen"
, and"rejected"
. - Preference dataset with implicit prompt:
"chosen"
and"rejected"
. - Unpaired preference dataset:
"prompt"
,"completion"
, and"label"
.
For keys
"messages"
,"prompt"
,"chosen"
,"rejected"
, and"completion"
, the values are lists of messages, where each message is a dictionary with keys"role"
and"content"
. - Language modeling dataset:
- tokenizer (
PreTrainedTokenizer
) — The tokenizer to apply the chat template with.
Returns
Dict[str, str]
The formatted example with the chat template applied.
If the example is in a conversational format, apply a chat template to it.
Note:
This function does not alter the keys, except for Language modeling dataset, where "messages"
is replaced by
"text"
.
Example:
>>> from transformers import AutoTokenizer
>>> tokenizer = AutoTokenizer.from_pretrained("microsoft/Phi-3-mini-128k-instruct")
>>> example = {
... "prompt": [{"role": "user", "content": "What color is the sky?"}],
... "completion": [{"role": "assistant", "content": "It is blue."}]
... }
>>> apply_chat_template(example, tokenizer)
{'prompt': '<|user|>\nWhat color is the sky?<|end|>\n<|assistant|>\n', 'completion': 'It is blue.<|end|>\n<|endoftext|>'}
Extracts the shared prompt from a preference data example, where the prompt is implicit within both the chosen and rejected completions.
For more details, see maybe_extract_prompt().
trl.maybe_extract_prompt
< source >( example: Dict ) → Dict[str, List]
Parameters
- example (
Dict[str, List]
) — A dictionary representing a single data entry in the preference dataset. It must contain the keys"chosen"
and"rejected"
, where each value is either conversational or standard (str
).
Returns
Dict[str, List]
A dictionary containing:
"prompt"
: The longest common prefix between the “chosen” and “rejected” completions."chosen"
: The remainder of the “chosen” completion, with the prompt removed."rejected"
: The remainder of the “rejected” completion, with the prompt removed.
Extracts the shared prompt from a preference data example, where the prompt is implicit within both the chosen and rejected completions.
If the example already contains a "prompt"
key, the function returns the example as is. Else, the function
identifies the longest common sequence (prefix) of conversation turns between the “chosen” and “rejected”
completions and extracts this as the prompt. It then removes this prompt from the respective “chosen” and
“rejected” completions.
Examples:
>>> example = {
... "chosen": [
... {"role": "user", "content": "What color is the sky?"},
... {"role": "assistant", "content": "It is blue."}
... ],
... "rejected": [
... {"role": "user", "content": "What color is the sky?"},
... {"role": "assistant", "content": "It is green."}
... ]
... }
>>> extract_prompt(example)
{'prompt': [{'role': 'user', 'content': 'What color is the sky?'}],
'chosen': [{'role': 'assistant', 'content': 'It is blue.'}],
'rejected': [{'role': 'assistant', 'content': 'It is green.'}]}
Or, with the map
method of datasets.Dataset
:
>>> from trl import extract_prompt
>>> from datasets import Dataset
>>> dataset_dict = {
... "chosen": [
... [
... {"role": "user", "content": "What color is the sky?"},
... {"role": "assistant", "content": "It is blue."},
... ],
... [
... {"role": "user", "content": "Where is the sun?"},
... {"role": "assistant", "content": "In the sky."},
... ],
... ],
... "rejected": [
... [
... {"role": "user", "content": "What color is the sky?"},
... {"role": "assistant", "content": "It is green."},
... ],
... [
... {"role": "user", "content": "Where is the sun?"},
... {"role": "assistant", "content": "In the sea."},
... ],
... ],
... }
>>> dataset = Dataset.from_dict(dataset_dict)
>>> dataset = dataset.map(extract_prompt)
>>> dataset[0]
{'prompt': [{'role': 'user', 'content': 'What color is the sky?'}],
'chosen': [{'role': 'assistant', 'content': 'It is blue.'}],
'rejected': [{'role': 'assistant', 'content': 'It is green.'}]}
trl.unpair_preference_dataset
< source >( dataset: DatasetType num_proc: Optional = None desc: Optional = None ) → Dataset
Parameters
- dataset (
Dataset
orDatasetDict
) — Preference dataset to unpair. The dataset must have columns"chosen"
,"rejected"
and optionally"prompt"
. - num_proc (
Optional[int]
, optional, defaults toNone
) — Number of processes to use for processing the dataset. - desc (
str
orNone
, optional, defaults toNone
) — Meaningful description to be displayed alongside with the progress bar while mapping examples.
Returns
Dataset
The unpaired preference dataset.
Unpair a preference dataset.
Example:
>>> from datasets import Dataset
>>> dataset_dict = {
... "prompt": ["The sky is", "The sun is"]
... "chosen": [" blue.", "in the sky."],
... "rejected": [" green.", " in the sea."]
... }
>>> dataset = Dataset.from_dict(dataset_dict)
>>> dataset = unpair_preference_dataset(dataset)
>>> dataset
Dataset({
features: ['prompt', 'completion', 'label'],
num_rows: 4
})
>>> dataset[0]
{'prompt': 'The sky is', 'completion': ' blue.', 'label': True}
trl.maybe_unpair_preference_dataset
< source >( dataset: DatasetType num_proc: Optional = None desc: Optional = None ) → Dataset
or DatasetDict
Parameters
- dataset (
Dataset
orDatasetDict
) — Preference dataset to unpair. The dataset must have columns"chosen"
,"rejected"
and optionally"prompt"
. - num_proc (
Optional[int]
, optional, defaults toNone
) — Number of processes to use for processing the dataset. - desc (
str
orNone
, optional, defaults toNone
) — Meaningful description to be displayed alongside with the progress bar while mapping examples.
Returns
Dataset
or DatasetDict
The unpaired preference dataset if it was paired, otherwise the original dataset.
Unpair a preference dataset if it is paired.
Example:
>>> from datasets import Dataset
>>> dataset_dict = {
... "prompt": ["The sky is", "The sun is"]
... "chosen": [" blue.", "in the sky."],
... "rejected": [" green.", " in the sea."]
... }
>>> dataset = Dataset.from_dict(dataset_dict)
>>> dataset = unpair_preference_dataset(dataset)
>>> dataset
Dataset({
features: ['prompt', 'completion', 'label'],
num_rows: 4
})
>>> dataset[0]
{'prompt': 'The sky is', 'completion': ' blue.', 'label': True}