pietrolesci/nli_fever

Overview

The original dataset can be found here while the Github repo is here.

This dataset has been proposed in Combining fact extraction and verification with neural semantic matching networks. This dataset has been created as a modification of FEVER.

In the original FEVER setting, the input is a claim from Wikipedia and the expected output is a label. However, this is different from the standard NLI formalization which is basically a pair-of-sequence to label problem. To facilitate NLI-related research to take advantage of the FEVER dataset, the authors pair the claims in the FEVER dataset with the textual evidence and make it a pair-of-sequence to label formatted dataset.

Dataset curation

The label mapping follows the paper and is the following

mapping = {
    "SUPPORTS": 0,  # entailment
    "NOT ENOUGH INFO": 1,  # neutral
    "REFUTES": 2,  # contradiction
}

Also, the "verifiable" column has been encoded as follows

mapping = {"NOT VERIFIABLE": 0, "VERIFIABLE": 1}

Finally, a consistency check with the labels reported in the original FEVER dataset is performed.

NOTE: no label is available for the "test" split. NOTE: there are 3 instances in common between dev and train splits.

Code to generate the dataset

import pandas as pd
from datasets import Dataset, ClassLabel, load_dataset, Value, Features, DatasetDict
import json


# download data from https://www.dropbox.com/s/hylbuaovqwo2zav/nli_fever.zip?dl=0
paths = {
    "train": "<some_path>/nli_fever/train_fitems.jsonl",
    "validation": "<some_path>/nli_fever/dev_fitems.jsonl",
    "test": "<some_path>/nli_fever/test_fitems.jsonl",
}


# parsing code from https://github.com/facebookresearch/anli/blob/main/src/utils/common.py
registered_jsonabl_classes = {}


def register_class(cls):
    global registered_jsonabl_classes
    if cls not in registered_jsonabl_classes:
        registered_jsonabl_classes.update({cls.__name__: cls})


def unserialize_JsonableObject(d):
    global registered_jsonabl_classes
    classname = d.pop("_jcls_", None)
    if classname:
        cls = registered_jsonabl_classes[classname]
        obj = cls.__new__(cls)  # Make instance without calling __init__
        for key, value in d.items():
            setattr(obj, key, value)
        return obj
    else:
        return d


def load_jsonl(filename, debug_num=None):
    d_list = []
    with open(filename, encoding="utf-8", mode="r") as in_f:
        print("Load Jsonl:", filename)
        for line in in_f:
            item = json.loads(line.strip(), object_hook=unserialize_JsonableObject)
            d_list.append(item)
            if debug_num is not None and 0 < debug_num == len(d_list):
                break

    return d_list


def get_original_fever() -> pd.DataFrame:
    """Get original fever datasets."""

    fever_v1 = load_dataset("fever", "v1.0")
    fever_v2 = load_dataset("fever", "v2.0")

    columns = ["id", "label"]
    splits = ["paper_test", "paper_dev", "labelled_dev", "train"]
    list_dfs = [fever_v1[split].to_pandas()[columns] for split in splits]
    list_dfs.append(fever_v2["validation"].to_pandas()[columns])

    dfs = pd.concat(list_dfs, ignore_index=False)
    dfs = dfs.drop_duplicates()

    dfs = dfs.rename(columns={"label": "fever_gold_label"})
    return dfs


def load_and_process(path: str, fever_df: pd.DataFrame) -> pd.DataFrame:
    """Load data split and merge with fever."""

    df = pd.DataFrame(load_jsonl(path))
    df = df.rename(columns={"query": "premise", "context": "hypothesis"})

    # adjust dtype
    df["cid"] = df["cid"].astype(int)

    # merge with original fever to get labels
    df = pd.merge(df, fever_df, left_on="cid", right_on="id", how="inner").drop_duplicates()

    return df


def encode_labels(df: pd.DataFrame) -> pd.DataFrame:
    """Encode labels using the mapping used in SNLI and MultiNLI"""
    mapping = {
        "SUPPORTS": 0,  # entailment
        "NOT ENOUGH INFO": 1,  # neutral
        "REFUTES": 2,  # contradiction
    }
    df["label"] = df["fever_gold_label"].map(mapping)

    # verifiable
    df["verifiable"] = df["verifiable"].map({"NOT VERIFIABLE": 0, "VERIFIABLE": 1})

    return df


if __name__ == "__main__":
    fever_df = get_original_fever()

    dataset_splits = {}

    for split, path in paths.items():

        # from json to dataframe and merge with fever
        df = load_and_process(path, fever_df)

        if not len(df) > 0:
            print(f"Split `{split}` has no matches")
            continue

        if split == "train":
            # train must have same labels
            assert sum(df["fever_gold_label"] != df["label"]) == 0

        # encode labels using the default mapping used by other nli datasets
        # i.e, entailment: 0, neutral: 1, contradiction: 2
        df = df.drop(columns=["label"])
        df = encode_labels(df)

        # cast to dataset
        features = Features(
            {
                "cid": Value(dtype="int64", id=None),
                "fid": Value(dtype="string", id=None),
                "id": Value(dtype="int32", id=None),
                "premise": Value(dtype="string", id=None),
                "hypothesis": Value(dtype="string", id=None),
                "verifiable": Value(dtype="int64", id=None),
                "fever_gold_label": Value(dtype="string", id=None),
                "label": ClassLabel(num_classes=3, names=["entailment", "neutral", "contradiction"]),
            }
        )
        if "test" in path:
            # no features for test set
            df["label"] = -1
            df["verifiable"] = -1
            df["fever_gold_label"] = "not available"
        dataset = Dataset.from_pandas(df, features=features)
        dataset_splits[split] = dataset

    nli_fever = DatasetDict(dataset_splits)
    nli_fever.push_to_hub("pietrolesci/nli_fever", token="<your token>")
    
    # check overlap between splits
    from itertools import combinations
    for i, j in combinations(dataset_splits.keys(), 2):
        print(
            f"{i} - {j}: ",
            pd.merge(
                dataset_splits[i].to_pandas(), 
                dataset_splits[j].to_pandas(), 
                on=["premise", "hypothesis", "label"], 
                how="inner",
            ).shape[0],
        )
    #> train - dev:  3
    #> train - test:  0
    #> dev - test:  0